(完整版)电机学英文文献翻译
机电一体化中英文对照外文翻译文献
中英文对照外文翻译文献(文档含英文原文和中文翻译)By integration of machinery developmentThe modern science and technology unceasing development, impelled different discipline intersecting enormously with the seepage, has caused the project domain technological revolution and the transformation, in mechanical engineering domain, because the microelectronic technology and the computer technology rapid development and forms to the mechanical industry seepage the integration of machinery, caused the mechanical industry the technical structure, the product organization, the function and the constitution, the production method and the management system has had the huge change, caused the industrial production to enter into “the integration of machinery” by “the machinery electrification” for the characteristic development phase.First, the integration of machinery outlineIntegration of machinery is refers in the organization new owner function, the power function, in the information processing functio n and the control function introduces the electronic technology, u nifies the system the mechanism and the computerization design and the software which constitutes always to call.Integration of machinery is refers in the organization new owner function, the power function, in the information processing functio n and the control function introduces the electronic technology, u nifies the system the mechanism and the computerization design and the software which constitutes always to call.The integration of machinery development also has become one to h ave until now own system new discipline, not only develops along with the science and technology, but also entrusts with the new content, but its basic characteristic may summarize is: The inte gration of machinery is embarks from the system viewpoint, synthes is community technologies and so on utilization mechanical technolo gy, microelectronic technology, automatic control technology, compute r technology, information technology, sensing observation and contro l technology, electric power electronic technology, connection techn ology, information conversion technology as well as software progra mming technology, according to the system function goal and the o ptimized organization goal, reasonable disposition and the layout v arious functions unit, in multi-purpose, high grade, redundant reli able, in the low energy consumption significance realize the speci fic function value, and causes the overall system optimization the systems engineering technology, from this produces function system , then becomes an integration of machinery systematic or the inte gration of machinery product.Therefore, “the integration of machinery”covering “the technolog y”and “the product”two aspects, only are, the integration of machinery technology is based on the above community technology organic fusion one kind of comprehensive technology, but is not m echanical technical, the microelectronic technology as well as othe r new technical simple combination, pieces together, this is the integration of machinery and the machinery adds the machinery elec trification which the electricity forms in the concept basic diffe rence, the mechanical engineering technology has the merely technic al to develop the machinery electrification, still was the traditi onal machinery, its main function still was replaces with the enl argement physical strength, after but developed the integration of machinery, micro electron installment eliminated may substitute fo r certain mechanical parts original Outside function, but also can entrust with many new functions, like the automatic detection, t he automatic reduction information, demonstrate the record, the aut omatic control and the control automatic diagnosis and the protect ion automatically and so on, not only namely the integration of machinery product is human's hand and body extending, human's sens e organ and the brains look, has the intellectualized characteristic is the integration of machinery and the machinery electrificati on distinguishes in the function essence.Second, the integration of machinery development conditionIntegration of machinery development may divide into 3 stages roug hly, 20th century 60's before for the first stage, this stage is called the initial stage, in this time, the people determination not on own initiative uses the electronic technology the prelimi nary achievement to consummate the mechanical product the performan ce, specially in Second World War period, the war has stimulated the mechanical product and the electronic technology union, these mechanical and electrical union military technology, postwar trans fers civilly, to the postwar economical restoration positive functi on, has developed and the development at that time generally spea king also is at the spontaneous condition, because at that time the electronic technology development not yet achieved certainly Le vel. Mechanical technical and electronic technology union also not impossible widespread and thorough development, already developed the product was also unable to promote massively.The 20th century 70~80 ages for the second stage, may be called the vigorous development stage, this time, the computer technology, the control technology, the communication development, has laid the technology base for the integration of machinery development, large-scale, ultra large scale integrated circuit and microcomputer swift and violent development, has provided the full material base for the integration of machinery development, this time characteristic is:①A mechatronics word first generally is accepted in Japan, probably obtains the quite widespread acknowledgment to 1980s last stages in the worldwide scale;②The integration of machinery technology and the product obtained the enormous development;③The various countries start to the integration of machinery technology and the product give the very big attention and the support. 1990s later periods, started the integration of machinery technology the new stage which makes great strides forward to the intelle ctualized direction, the integration of machinery enters the thorou gh development time, on the one hand, optics, the communication a nd so on entered the integration of machinery, processes the tech nology also zhan to appear tiny in the integration of machinery the foot, appeared the light integration of machinery and the micro integration of machinery and so on the new branch; On the ot her hand to the integration of machinery system modelling design, the analysis and the integrated method, the integration of machi nery discipline system and the trend of development has all condu cted the thorough research, simultaneously, because domains and soon artificial intelligence technology, neural network technology a nd optical fiber technology obtain the huge progress, opened the development vast world for the integration of machinery technology,these research, will urge the integration of machinery further t o establish the integrity the foundation and forms the integrity gradually the scientific system.Third, the integration of machinery trend of developmentIntegration of machinery is the collection machinery, the electron, optics, the control, the computer, the information and so on th e multi-disciplinary overlapping syntheses, its development and the progress rely on and promote the correlation technology developme nt and the progress, therefore, the integration of machinery main development direction is as follows:3.1IntellectualizedIntellectualization is a 21st century integration of machinery tech nological development important development direction, the artificial intelligence obtains day by day in the integration of machinery constructor's research takes, the robot and the numerical control engine bed intellectualization is the important application, here said “the intellectualization”is to the machine behavior descr iption, is in the control theory foundation, the absorption artifi cial intelligence, the operations research, the computer science, t he fuzzy mathematics, the psychology, the physiology and the chaos dynamics and so on the new thought, the new method, simulate t he human intelligence, enable it to have abilities and so on j udgment inference, logical thinking, independent decision-making, obt ains the higher control goal in order to, indeed, enable the int egration of machinery product to have With the human identical in telligence, is not impossible, also is nonessential, but, the high performance, the high speed microprocessor enable the integration of machinery product to have .preliminary intelligent or human's partial intelligences, then is completely possible and essential.3.2 ModularModulations are one item important and the arduous project, becaus e the integration of machinery product type and the manufacturer are many, but the development and the development have standard m echanical connection, electrical connection, power connection, the e nvironment connection integration of machinery product unit are an item extremely complex also are the extremely important matters, like the development collection deceleration, the intelligent velo city modulation, the electrical machinery in a body power unit, h ave function and so on vision, imagery processing, recognition and range finder control units, as well as each kind can complete the model operation the mechanism, like this, may use the standar d unit to develop the new product rapidly, simultaneously also ma y expand the scale of production, this need formulation Each standard, in order to various parts, the unit match and the connecti on, as a result of the conflicts of interest, very will be diff icult to formulate international or the domestic this aspect stand ard in the near future, but might through set up some big enter prises to8 form gradually, obviously, the advantage which from the el ectrical product standardization, the seriation will bring may af firm, regardless of will be to produces the standard integration of machinery unit the enterprise to produce the integration of ma chinery product the enterprise, the formalization will give the in tegration of machinery enterprise to bring the happy future3.3 Network1990s, the computer technology and so on the prominent achievement was the networking, networking starting with the rapid developmen t for the science and technology, the industrial production, polit ical, the military, the education magnanimous act person daily l ife has all brought the huge transformation, each kind of network the global economy, the production linked up into a single stre tch, enterprise's competition will also globalize, once the integra tion of machinery new product developed, so long as its function were original, the quality was reliable, very quick could the b est-selling whole world, as a result of the network popularization , was on the rise based on network each kind of long-distance c ontrol and the surveillance technology, but long-distance control t erminal device itself will be the integration of machinery product , the field busWas the domestic electric appliances network has9 become the situation with the local area network technolog y, connected using the family network each kind of domestic elect ric appliances take the computer as the central computer integrati on electrical appliances system, caused the people at home to sha re the inconvenience and the joy which each kind of high-tech br ought, therefore, the integration of machinery product faced the n etwork direction to develop without doubt.3.4 MicrominiaturizedMicrominiaturization emerge in the end of 1980s, refers is the in tegration of machinery to the miniature machine and the microscopi c domain development tendency, overseas name it micro electron mec hanical system (MEMS), makes a general reference the geometry size not to surpass 1cm3 the integration of machinery product, and t o micron, the nanometer level development, the micro integration o f machinery product volume small, consumes energy few, the movemen t is nimble, in aspects and so on biological medical service, mi litary, information has the incomparable superiority, the micro int egration of machinery development bottleneck lies in the micro mechanical technology, the micro integration of machinery product proc essing uses the fine processing technology, namely ultra precise t echnology, it including photoetching technology and etching technolo gy two kinds.3.5 GreenIndustries lived developed for the people have brought the huge c hange, on the one hand, the material was rich, the life was com fortable; On the other hand, the resources reduce, the ecological environment receives the serious pollution, therefore, the people appealed the protection environment resources, the return nature, the green product concept arises at the historic moment under t his kind of call, the green is the time tendency, the green pro duct in its design, the manufacture, the use and in the destruct ion life process, conforms to the specific environmental protection and the human health request, harmless or the harm are extremel y few to the ecological environment, the resources use factor is extremely high, the design green integration of machinery product , has the broad development future, the integration of machinery product green mainly is refers, when use does not pollute the ec ological environment, after the abandonment can recycle the use. 3.6 systematizationsOne of systematized performance characteristics is the system archi tecture further uses open style and the patternizing main line st ructure. the system may the nimble configuration, carries on tailo rs and the combination willfully, simultaneously seeks realizes the multi-subsystem coordination control and the synthesis management, second performance is the correspondence function big enhancement, generally besides RS232, but also will have RS485, the DCS pers onification, the future integration of machinery even more pays gr eat attention to the product and human's relations, the integratio n of machinery personification will have two meanings, one will b e, the integration of machinery product finally user will be a h uman, how will entrust with the integration of machinery product person's intelligence, the emotion, the human nature appears more and more importantly, specially the opposite partyWith the robot, its high-level boundary is the man-machine integration, another imi tates the biological mechanism, develops each kind of mechanical a nd electrical body flower product, in fact, many integration of m achinery products all are developed animal's inspiration.Fourth, the model integration of machinery productIntegration of machinery product subsystem (complete machine) and t he foundation Yuan, the part two big kinds, the typical integrati on of machinery system includes: The numerical control engine bed, the robot, the automobile computerization product,12 the intellectualized instrument measuring appliance, the elec tronic publishing printing system, the CAD/CAM system and so on, the typical integration of machinery Yuan, the part includes: Elec tric power electronic device and equipment, programmable controller, fuzzy controller, miniature electrical machinery, sensor, special-p urpose integrated circuit, servo and so on, these model integratio n of machinery product technical present situation, trend of devel opment, market prospect analysis omitting.Fifth, our country develops the situation and the duty integration of machinery work which “The integration of machinery” faces mainly includes two levels: One, with the microelectronic technology transformation tradition industry, its goal is the energy conservation, the nodal wood, enhances the work efficiency, improves the product quality, enhances the traditional industry technology advancement one step; Two, development automation, digitization, intellectualized mechanical and electrical products, promotion product renewal.(1) our country “the integration of machinery†the work fac es situation1. Our country is big with the microelectronic technology transfor mation tradition industry work load and is broad, has difficulty2. Our country with the integration of machinery technology accele ration product renewal, enhances the market share the call to be high, has the pressure.3.Our country is low with the integration of machinery product su bstitution technology content and the added value, consumes energy, the water consumption, consumes the material to be high, the po llution, harasses the people product the responsibility to be heav y, has the significance, in our country industrial system, the en ergy consumption, the water consumption wealthy and powerful family , also accounts for the quite great proportion to the environment al pollution serious enterprise, in recent years our country's ind ustry structure, product mix although several passes through the adjustment, but because many kinds of reasons, the result contin uously insufficiently is obvious, inside this no doubt has the hi gher authority to lead the department the policy comes out of ma ny doors question, “therefore has the enterprise “to hate to le ave one's native land”clings to tenaciously industry”the quest ion, but undeniable also has cannot optimize the ideal industry, optimal pleasing product The question, on the good answer already suspended at these enterprise's front, this was the development integration of machinery, developed with the production related int egration of14 machinery product, the integration of machinery product fu nction strong, the performance good, the quality high, the cost was low, also had the flexibility, might according to when the ma rket requirement and the user reflection the product mix and the production process made the essential adjustment, the reform, but did not need to change the equipment, this was the solution me chanical and electrical products multi-varieties, the few volume pr oduction important outlet, simultaneously, might pour into the fres h blood for the traditional mechanical industry, brought the new vigor, extricated the machinery production from the arduous physica l labor, realization Enlightened production.Moreover, looked from the market demand angle, because our country develops, the development integration of machinery product history is not long, the disparity is big, many product varieties, quan tity, the scale, the quality all cannot meet the need, the impor t volume all quite is big every year, therefore must develop urg ently.(2) Our country “the integration of machinery†work duty Our country may summarize in the integration of machinery aspect duty is two speeches: A speech widely thoroughly uses the integra tion of machinery technological transformations tradition industry; Another speech is develops the integration of15 machinery product on a grand scale, the promotion mechani cal and electrical products renewal, the total goal is the promot ion mechanical and electrical body industry formation, makes the c ontribution for our country industrial structure and the product m ix adjustment.In brief, the integration of machinery technology not only is pro motes the traditional mechanical and electrical industry fresh bloo d and the source power, also is opens our country mechanical and electrical profession product mix, the industrial structure adjust s the front door the key.Sixth, our country develops “the integration of machinery†c ountermeasure(1) Enhancement overall plan arrangement, coordinated development pl anAt present, our country is engaged in the unit which “the integ ration of machinery”the research develops and produces to be ve ry many, each one all has a set of own development strategy, va rious units' plan as a result of respective standpoint, the objec tive point limit, only is considered unavoidably the local interes t, various16 department responsible for the work's related plan and pl an, also some unification consideration insufficiency, the overall plan arrangement insufficient question, simultaneously lacks the com prehensive survey overall situation to have the authority development plan and the strategic plan, therefore, suggested various depar tment responsible for the work charges the unit concerned in to conduct the thorough investigation and study, in the scientific an alysis foundation, formulates manages the overall situation “the i ntegration of machinery”the research, the development, the produc tive plan and the plan Avoids developing duplicates, produces hasa collision!(2) Strengthened profession management, display “associationâ€functionAt present, our country “integration of machinery”hot, but acco rding to the present profession division method and the management system, “the policy comes out of many doors”is difficult duo , therefore, our country has the necessity to be clear about one “the integration of machinery”the profession to manage the or ganization, according to the present country political reform and the economic restructuring spirit, as well as the integration of machinery profession characteristic, we suggested, strengthens Beijin g Integration of machinery Association as soon as possible the co nstruction, entrusts with its profession management function, “the association”must further expand the leadership organization - -council representative the stratification plane and the coverage, must strengthen the office, secretariat's construction; Must throu gh its astute capable administrative body, the economic entity, the organization17 “the profession”the development plan, strategic plan dr awing up; The instruction profession stationing layout adjustment, carries on develops the breach choice, pays special attention to the priority project the experiment site and the related project loses one's temper, the tender work ......Seventh, the conclusionIn summary, the integration of machinery appearance is not isolate d, it is many science and technology development crystallization, is the social productive forces develops the certain stage inevita bly request Certainly, also has with the integration of machinery related technology very many, and along with the science and te chnology development, the tendency which each kind of technology w ill fuse mutually more and more is obvious, the integration of m achinery technology broad prospects for development more and more will be also bright.论机电一体化的发展现代科学技术的不断发展，极大地推动了不同学科的交叉与渗透，导致了工程领域的技术革命与改造,在机械工程领域，由于微电子技术和计算机技术的迅速发展及其向机械工业的渗透所形成的机电一体化，使机械工业的技术结构、产品机构、功能与构成、生产方式及管理体系发生了巨大变化，使工业生产由“机械电气化”迈入了“机电一体化”为特征的发展阶段。
直流电动机中英文对照外文翻译文献
中英文对照外文翻译文献(文档含英文原文和中文翻译)外文文献：DC Motor CalculationsOverviewNow that we have a good understanding of dc generators, we can begin our study of dc motors. Direct-current motors transform electrical energy into mechanical energy. They drive devices such as hoists, fans, pumps, calendars, punch-presses, and cars. These devices may have a definite torque-speed characteristic (such as a pump or fan) or a highly variable one (such as a hoist or automobile). The torque-speed characteristic of the motor must be adapted to the type of the load it has to drive, and this requirement has given rise to three basic types of motors: 1.Shunt motors 2. Series motors 3. Compound motors Direct-current motors are seldom used in ordinary industrial applications because all electric utility systems furnish alternating current. However, for special applications such as in steel mills, mines, and electric trains, it is sometimes advantageous to transform the alternating current into direct current in order to use dc motors. The reason is that the torque-speed characteristics of dc motors can be varied over a wide range while retaining high efficiency. Today, this general statement can be challenged because the availability of sophisticated electronic drives has made it possible to use alternating current motors for variable speed applications. Nevertheless, there are millions of dc motors still in service and thousands more are being produced every year.Counter-electromotive force (cemf)Direct-current motors are built the same way as generators are; consequently, a dc machine can operate either as a motor or as a generator. To illustrate, consider a dc generator in which the armature, initially at rest, is connected to a dc source E s by means of a switch (Fig. 5.1). The armature has a resistance R, and the magnetic field is created by a set of permanent magnets.As soon as the switch is closed, a large current flows in the armature because its resistance is very low. The individual armature conductors are immediately subjected to a force because they are immersed in the magnetic field created by the permanent magnets. These forces add upto produce a powerful torque, causing the armature to rotate.Figure 5.1 Starting a dc motor across the line.On the other hand, as soon as the armature begins to turn, a second phenomenon takes place: the generator effect. We know that a voltage E o is induced in the armature conductors as soon as they cut a magnetic field (Fig. 5.2). This is always true, no matter what causes the rotation. The value and polarity of the induced voltage are the same as those obtained when the machine operates as a generator. The induced voltage E o is therefore proportional to the speed of rotation n of the motor and to the flux F per pole, as previously given by Eq. 5.1:E o = Zn F/60 (5.1)As in the case of a generator, Z is a constant that depends upon the number of turns on the armature and the type of winding. For lap windings Z is equal to the number of armature conductors.In the case of a motor, the induced voltage E o is called counter-electromotive force (cemf) because its polarity always acts against the source voltage E s. It acts against the voltage in the sense that the net voltage acting in the series circuit of Fig. 5.2 is equal to (E s - Eo) volts and not (E s + E o) volts.Figure 5.2 Counter-electromotive force (cemf) in a dc motor.Acceleration of the motorThe net voltage acting in the armature circuit in Fig. 5.2 is (E s- E o) volts. The resulting armature current /is limited only by the armature resistance R, and soI = (E s- E o)IR (5.2)When the motor is at rest, the induced voltage E o= 0, and so the starting current isI = E s/RThe starting current may be 20 to 30 times greater than the nominal full-load current of the motor. In practice, this would cause the fuses to blow or the circuit-breakers to trip. However, if they are absent, the large forces acting on the armature conductors produce a powerful starting torque and a consequent rapid acceleration of the armature.As the speed increases, the counter-emf E o increases, with the result that the value of (E s—E o)diminishes. It follows from Eq. 5.1 that the armature current / drops progressively as the speed increases.Although the armature current decreases, the motor continues to accelerate until it reaches a definite, maximum speed. At no-load this speed produces a counter-emf E o slightly less than the source voltage E s. In effect, if E o were equal to E s the net voltage (E s—E o) would become zero and so, too, would the current /. The driving forces would cease to act on the armature conductors, and the mechanical drag imposed by the fan and the bearings would immediately cause the motor to slow down. As the speed decreases the net voltage (E s—E o) increases and so does the current /. The speed will cease to fall as soon as the torque developed by the armature current is equal to the load torque. Thus, when a motor runs at no-load, the counter-emf must be slightly less than E s so as to enable a small current to flow, sufficient to produce the required torque.Mechanical power and torqueThe power and torque of a dc motor are two of its most important properties. We now derive two simple equations that enable us to calculate them.1. According to Eq. 5.1 the cemf induced in a lap-wound armature is given byE o = Zn F/60Referring to Fig. 5.2, the electrical power P a supplied to the armature is equal to the supply voltage E s multiplied by the armature current I:P a = E s I (5.3)However, E s is equal to the sum of E o plus the IR drop in the armature:E s = E o + IR (5.4)It follows thatP a= E s I= (E o + IR)I=E o I + I2R (5.5)The I2R term represents heat dissipated in the armature, but the very important term E o I is the electrical power that is converted into mechanical power. The mechanical power of the motor is therefore exactly equal to the product of the cemf multiplied by the armature currentP = E o I (5.6)whereP = mechanical power developed by the motor [W]E o= induced voltage in the armature (cemf) [V]I = total current supplied to the armature [A]2. Turning our attention to torque T, we know that the mechanical power P is given by the expressionP = nT/9.55 (5.7)where n is the speed of rotation.Combining Eqs. 5.7,5.1, and 5.6, we obtainnT/9.55 = E o I= ZnFI/60and soT =Z F I/6.28The torque developed by a lap-wound motor is therefore given by the expressionT =Z F I/6.28 (5.8)whereT = torque [N×m]Z = number of conductors on the armatureF = effective flux per pole [Wb]*/ = armature current [A]6.28 = constant, to take care of units[exact value = 2p]Eq. 5.8shows that we can raise the torque of a motor either by raising the armature current or by raising the flux created by the poles.Speed of rotationWhen a dc motor drives a load between no-load and full-load, the IR drop due to armature resistance is always small compared to the supply voltage E s. This means that the counter-emf E s is very nearly equal to E s.On the other hand, we have already seen that Eo may be expressed by the equationE o = Zn F/60Replacing E o by E s we obtainE s = Zn F/60That is,wheren = speed of rotation [r/min]E s = armature voltage [V]Z = total number of armature conductorsThis important equation shows that the speed of the motor is directly proportional to the armature supply voltage and inversely proportional to the flux per pole. We will now study how this equation is applied.Armature speed controlAccording to Eq. 5.8, if the flux per pole F is kept constant (permanent magnet field or field with fixed excitation), the speed depends only upon the armature voltage E s. By raising or lowering E s the motor speed will rise and fall in proportion.In practice, we can vary E s by connecting the motor armature M to a separately excited variable-voltage dc generator G . The field excitation of the motor is kept constant, but the generator excitation I x can be varied from zero to maximum and even reversed. The generator output voltage E s can therefore be varied from zero to maximum, with either positive or negative polarity. Consequently, the motor speed can be varied from zero to maximum in either direction. Note that the generator is driven by an ac motor connected to a 3-phase line. This method of speed control, known as the Ward-Leonard system, is found in steel mills, high-rise elevators, mines, and paper mills.In modem installations the generator is often replaced by a high-power electronic converter that changes the ac power of the electrical utility to dc, by electronic means.What happens to the dc power received by generator G? When G receives electric power, it operates as a motor, driving its own ac motor as an asynchronous generator!* As a result, ac power is fed back into the line that normally feeds the ac motor. The fact that power can be recovered this way makes the Ward-Leonard system very efficient, and constitutes another of its advantages.Rheostat Speed ControlAnother way to control the speed of a dc motor is to place a rheostat in series with the armature . The current in the rheostat produces a voltage drop which subtracts from the fixed source voltage E s, yielding a smaller supply voltage across the armature. This method enables us to reduce the speed below its nominal speed. It is only recommended for small motors because a lot of power and heat is wasted in the rheostat, and the overall efficiency is low. Furthermore, thespeed regulation is poor, even for a fixed setting of the rheostat. In effect, the IR drop across the rheostat increases as the armature current increases. This produces a substantial drop in speed with increasing mechanical load.中文译文：直流电动机的计算概述现在，我们对直流发电机有一个很好的了解，我们可以开始对直流电动机的研究了。
机电专业英语翻译(中英文一行一行对照翻译)
专业英语(论文)英译汉课题名称机电专业英语学生姓名学号10411044系、年级专业10级机电一班指导教师2013年12月12日Design of StructuralMechanisms结构机制设计Melinda MayA dissertation submitted for the degree of Doctor of Philosophyin the Department of Engineering Science at the University of OxfordSt Hugh’s College牛津大学圣休斯学院工程科学系哲学博士学位论文Trinity Term 20032003年夏季学期Design of Structural Mechanisms结构机制设计Abstract摘要A dissertation submitted for the degree of Doctor of Philosophyin the Department of Engineering Science at the University of OxfordSt Hugh’s College牛津大学圣休斯学院工程科学系哲学博士学位论文Trinity Term 20032003年夏季学期In this dissertation, we explore the possibilities of systematically constructing largestructural mechanisms using existing spatial overconstrained linkages with onlyrevolute joints as basic elements.在这篇论文中，我们探讨利用只以旋转接头为基本元素的现存受空间限制过约束机构来系统地构建大型结构机制的可能性。
The first part of the dissertation is devoted to structural mechanisms (networks) basedon the Bennett linkage, a well-known spatial 4R linkage.该论文的第一部分专注于以贝内特机构为基础的结构机制（网络），一个众所周知的空间4R机构。
(完整版)电机学英文文献翻译
Widespread use in production machines without changing the synchronous speed of motor speed control method Wound Rotor Series Resistance Speed, chopper speed control, cascade control, and application of electromagnetic slip clutch, fluid couplings, clutches and other film speed. Change the synchronous speed of change on the number of stator pole multi-speed motor to change the stator voltage and frequency to frequency conversion with no change to the motor speed and so on.
Energy from the speed point of view when, with high speed method and inefficient methods of two kinds of speed: high speed when the slip refers to the same, so no slip losses, such as multi-speed motors, Slip frequency control and loss can speed recovery methods (such as cascade control, etc.). A deteriorating loss of speed control methods are inefficient speed, such as series resistance of the rotor speed method, the energy loss in the rotor circuit on; Electromagnetic Clutch The speed method, the energy loss in the clutch coils; fluid coupling speed, energy loss in the fluid coupling of the oil. General deterioration in loss increased with the expansion speed range, if not speed range, the energy loss is minimal.
同步电动机外文翻译文献
同步电动机外文翻译文献同步电动机外文翻译文献(文档含中英文对照即英文原文和中文翻译)Synchronous motorAbstract：In recent decades, with the power electronics, microelectronics technology and the development of modern controltheory, medium and small power motors in the industrial and agricultural production and people's daily lives are very broad application. Particularly in the township enterprises and household electrical appliances, need a large number of medium and small-power motors. Because of this motor development and wide application, its use, maintenance and repair work has become increasingly important，Here are just on the knowledge of synchronous motor1. Principle of operationIn order to understand the principle of operation of a synchronous motor, let us examine what happens if we connect the armature winding (laid out in the stator) of a 3-phase synchronous machine to a suitable balanced 3-phase source and the field winding to a D.C source of appropriate voltage. The current flowing through the field coils will set up stationary magnetic poles of alternate North and South.(for convenience let us assume as alient pole rotor, as shown in Fig. 50). On the other hand, the 3-phase currents flowing in the armature winding produce a rotating magnetic field rotating at synchronous speed. In other words there will be moving North and South poles established in the stator due to the 3-phase currents i.e at any location in the stator there will be a North pole at some instant of time and it will become a South pole after a time period corresponding to half a cycle. (after a time = 1/2f , where f = frequency of the supply). Let us assume that the stationarySouth pole in the rotor is aligned with the North pole in the stator moving in clockwise direction at a particular instant of time, as shown in Fig50. These two poles get attracted and Figure 50: Force of attraction between stator poles and rotor poles - resulting in production of torque in clockwise direction try to maintain this alignment ( as per L enz’s law) and hence the rotor pole tries to follow the stator pole as the conditions are suitable for the production of torque in the clockwise direction. However the rotor can not move instantaneously due to its mechanical inertia, and so it needs sometime to move. In the mean time, the stator pole would quickly (a time duration corresponding to half a cycle) change its polarity and becomes a South pole。
(完整版)电气专业中英文对照翻译毕业设计论文
优秀论文审核通过未经允许切勿外传Chapter 3 Digital Electronics3.1 IntroductionA circuit that employs a numerical signal in its operation is classified as a digital circuitputers,pocket calculators, digital instruments, and numerical control (NC) equipment are common applications of digital circuits. Practically unlimited quantities of digital information can be processed in short periods of time electronically. With operational speed of prime importance in electronics today,digital circuits are used more frequently.In this chapter, digital circuit applications are discussed.There are many types of digital circuits that electronics, including logic circuits, flip-flop circuits, counting circuits, and many others. The first sections of this unit discuss the number systems that are basic to digital circuit understanding. The remainder of the chapter introduces some of the types of digital circuits and explains Boolean algebra as it is applied to logic circuits.3.2 Digital Number SystemsThe most common number system used today is the decimal system,in which 10 digits are used for counting. The number of digits in the systemis called its base (or radix).The decimal system，therefore，the counting process. The largest digit that can be used in a specific place or location is determined by the base of the system. In the decimal system the first position to the left of the decimal point is called the units place. Any digit from 0 to 9 can be used in this place.When number values greater than 9 are used,they must be expressed with two or more places.The next position to the left of the units place in a decimal system is the tens place.The number 99 is the largest digital value that can be expressed by two places in the decimal system.Each place added to the left extends the number system by a power of 10.Any number can be expressed as a sum of weighted place values.The decimal number 2583,for example, is expressed as (2×1000)+(5×100)+(8×10)+(3×1).The decimal number system is commonly used in our daily lives. Electronically, the binary system.Electronically,the value of 0 can be associated with a low-voltage value or no voltage. The number 1 can then be associated with a voltage value larger than 0. Binary systems that use these voltage values are said to , this chapter.The two operational states of a binary system,1 and 0,are natural circuit conditions. When a circuit is turned off or the off, or 0,state. An electrical circuit that the on，or 1,state. By using transistor or ICs，it is electronically possible to change states in less than a microsecond. Electronic devices make it possible to manipulate millions of 0s and is in a second and thus to process information quickly.The basic principles of numbering used in decimal numbers apply ingeneral to binary numbers.The base of the binary system is 2,meaning that only the digits 0 and 1 are used to express place value. The first place to the left of the binary point,or starting point，represents the units，or is,location. Places to the left of the binary point are the powers of 2.Some of the place values in base 2 are 2º=1,2¹=2,2²=4,2³=8,2⁴=16,25=32,and 26=64.When bases other than 10 are used,the numbers should example.The number 100₂(read“one,zero,zero, base 2”)is equivalent to 4 in base 10,or 410.Starting with the first digit to the left of the binary point,this number this method of conversion a binary number to an equivalent decimal number，write down the binary number first. Starting at the binary point，indicate the decimal equivalent for each binary place location where a 1 is indicated. For each 0 in the binary number leave a blank space or indicate a 0 ' Add the place values and then record the decimal equivalent.The conversion of a decimal number to a binary equivalent is achieved by repetitive steps of division by the number 2.When the quotient is even with no remainder,a 0 is recorded.When the quotient process continues until the quotient is 0.The binary equivalent consists of the remainder values in the order last to first.3.2.2 Binary-coded Decimal (BCD) Number SystemWhen large numbers are indicated by binary numbers，they are difficult to use. For this reason，the Binary-Coded Decimal(BCD) method of counting was devised. In this system four binary digits are used to represent each decimal digit.To illustrate this procedure，the number 105，is converted to a BCD number.In binary numbers，To apply the BCD conversion process，the base 10 number is first divided into digits according to place values.The number 10510 gives the digits 1-0-5.Converting each displayed by this process with only 12 binary numbers. The between each group of digits is important when displaying BCD numbers.The largest digit to be displayed by any group of BCD numbers is 9.Six digits of a number-coding group are not used at all in this system.Because of this, the octal (base 8) and the binary form but usually display them in BCD,octal,or a base 8 system is 7. The place values starting at the left of the octal point are the powers of eight: 80=1,81=8,82=64,83=512,84=4096,and so on.The process of converting an octal number to a decimal number is the same as that used in the binary-to-decimal conversion process. In this method, equivalent decimal is 25810.Converting an octal number to an equivalent binary number is similar to the BCD conversion process. The octal number is first divided into digits according to place value. Each octal digit is then converted into an equivalent binary number using only three digits.Converting a decimal number to an octal number is a process of repetitive division by the number 8.After the quotient determined，the remainder is brought down as the place value.When the quotient is even with no remainder，a 0 is transferred to the place position.The number for converting 409810 to base 8 is 100028.Converting a binary number to an octal number is an importantconversion process of digital circuits. Binary numbers are first processed at a very output circuit then accepts this signal and converts it to an octal signal displayed on a readout device.must first be divided into groups of three，starting at the octal point.Each binary group is then converted into an equivalent octal number.These numbers are then combined，while remaining in their same respective places，to represent the equivalent octal number.3.2.4 Hexadecimal Number SystemThe digital systems to process large number values.The base of this system is 16，which means that the largest number used in a place is 15.Digits used by this system are the numbers 0-9 and the letters A-F. The letters A-P are used to denote the digits 10-15，respectively. The place values to the left of the .The process of changing a proper digital order.The place values，or powers of the base，are then positioned under the respective digits in step 2.In step 3，the value of each digit is recorded. The values in steps 2 and 3 are then multiplied together and added. The sum gives the decimal equivalent value of a . Initially，the converted to a binary number using four digits per group. The binary group is combined to form the equivalent binary number.The conversion of a decimal number to a ，as with other number systems. In this procedure the division is by 16 and remainders can be as large as 15.Converting a binary number to a groups of four digits，starting at the converted to a digital circuit-design applications binary signals arefar superior to those of the octal，decimal，or be processed very easily through electronic circuitry，since they can be represented by two stable states of operation. These states can be easily defined as on or off, 1 or 0，up or down，voltage or no voltage，right or left，or any other two-condition states. There must be no in-between state.The symbols used to define the operational state of a binary system are very important.In positive binary logic，the state of voltage，on，true，or a letter designation (such as A ) is used to denote the operational state 1 .No voltage，off，false，and the letter A are commonly used to denote the 0 condition. A circuit can be set to either state and will remain in that state until it is caused to change conditions.Any electronic device that can be set in one of two operational states or conditions by an outside signal is said to be bistable. Relays，lamps，switches，transistors, diodes and ICs may be used for this purpose. A bistable device .By using many of these devices，it is possible to build an electronic circuit that will make decisions based upon the applied input signals. The output of this circuit is a decision based upon the operational conditions of the input. Since the application of bistable devices in digital circuits makes logical decisions，they are commonly called binary logic circuits.If we were to draw a circuit diagram for such a system，including all the resistors，diodes，transistors and interconnections，we would face an overwhelming task, and an unnecessary one.Anyone who read the circuit diagram would in their mind group the components into standard circuits and think in terms of the" system" functions of the individual gates. Forthis reason，we design and draw digital circuit with standard logic symbols. Three basic circuits of this type are used to make simple logic decisions.These are the AND circuit, OR circuit, and the NOT circuit.Electronic circuits designed to perform logic functions are called gates.This term refers to the capability of a circuit to pass or block specific digital signals.The logic-gate symbols are shown in Fig.3-1.The small circle at the output of NOT gate indicates the inversion of the signal. Mathematically，this action is described as A=.Thus without the small circle，the rectangle would represent an amplifier (or buffer) with a gain of unity.An AND gate the 1 state simultaneously，then there will be a 1 at the output.The AND gate in Fig. 3-1 produces only a 1 out-put when A and B are both 1. Mathematically，this action is described as A·B=C. This expression shows the multiplication operation. An OR gate Fig.3-1 produces a when either or both inputs are l.Mathematically，this action is described as A+B=C. This expression shows OR addition. This gate is used to make logic decisions of whether or not a 1 appears at either input.An IF-THEN type of sentence is often used to describe the basic operation of a logic state.For example，if the inputs applied to an AND gate are all 1，then the output will be 1 .If a 1 is applied to any input of an OR gate，then the output will be 1 .If an input is applied to a NOT gate，then the output will be the opposite or inverse.The logic gate symbols in Fig. 3-1 show only the input and output connections. The actual gates，when wired into a digital circuit, would pin 14 and 7.3.4 Combination Logic GatesWhen a NOT gate is combined with an AND gate or an OR gate，it iscalled a combination logic gate. A NOT-AND gate is called a NAND gate，which is an inverted AND gate. Mathematically the operation of a NAND gate is A·B=. A combination NOT-OR ，or NOR，gate produces a negation of the OR function.Mathematically the operation of a NOR gate is A+B=.A 1 appears at the output only when A is 0 and B is 0.The logic symbols are shown in Fig. 3-3.The bar over C denotes the inversion，or negative function，of the gate.The logic gates discussed .In actual digital electronic applications，solid-state components are ordinarily used to accomplish gate functions.Boolean algebra is a special form of algebra that was designed to show the relationships of logic operations.Thin form of algebra is ideally suited for analysis and design of binary logic systems.Through the use of Boolean algebra，it is possible to write mathematical expressions that describe specific logic functions.Boolean expressions are more meaningful than complex word statements or or elaborate truth tables.The laws that apply to Boolean algebra are used to simplify complex expressions. Through this type of operation it may be possible to reduce the number of logic gates needed to achieve a specific function before the circuits are designed.In Boolean algebra the variables of an equation are assigned by letters of the alphabet.Each variable then exists in states of 1 or 0 according to its condition.The 1，or true state，is normally represented by a single letter such as A，B or C.The opposite state or condition is then described as 0，or false，and is represented by or A’.This is described as NOT A，A negated，or A complemented.Boolean algebra is somewhat different from conventional algebra withrespect to mathematical operations.The Boolean operations are expressed as follows:Multiplication:A AND B，AB，,A·BOR addition:A OR B .A+BNegation，or complementing:NOT A，，A’Assume that a digital logic circuit only C is on by itself or when A，B and C are all on expression describes the desired output. Eight (23) different combinations of A，B，and C exist in this expression because there are three，inputs. Only two of those combinations should cause a signal that will actuate the output. When a variable is not on (0)，it is expressed as a negated letter. The original statement is expressed as follows: With A，B，and C on or with A off, B off, and C on ，an output (X）will occur:ABC+C=XA truth table illustrates if this expression is achieved or not.Table 3-1 shows a truth table for this equation. First，ABC is determined by multiplying the three inputs together.A 1 appears only when the A，B，and C inputs are all 1.Next the negated inputs A andB are determined.Then the products of inputs C，A，and B are listed.The next column shows the addition of ABC and C.The output of this equation shows that output 1 is produced only when C is 1 or when ABC is 1.A logic circuit to accomplish this Boolean expression is shown in Fig. 3-4.Initially the equation is analyzed to determine its primary operational function.Step1 shows the original equation.The primary function is addition，since it influences all parts of the equation in some way.Step 2 shows the primary function changed to a logic gate diagram.Step 3 showsthe branch parts of the equation expressed by logic diagram，with AND gates used to combine terms.Step 4 completes the process by connecting all inputs together.The circles at inputs，of the lower AND gate are used to achieve the negative function of these branch parts.The general rules for changing a Boolean equation into a logic circuit diagram are very similar to those outlined.Initially the original equation must be analyzed for its primary mathematical function.This is then changed into a gate diagram that is inputted by branch parts of the equation.Each branch operation is then analyzed and expressed in gate form.The process continues until all branches are completely expressed in diagram formmon inputs are then connected together.3.5 Timing and Storage ElementsDigital electronics involves a number of items that are not classified as gates.Circuits or devices of this type the operation of a system.Included in this system are such things as timing devices，storage elements，counters，decoders，memory，and registers.Truth tables symbols，operational characteristics，and applications of these items will be presented an IC chip. The internal construction of the chip cannot be effectively altered. Operation is controlled by the application of an external signal to the input. As a rule，very little work can be done to control operation other than altering the input signal.The logic circuits in Fig. 3-4 are combinational circuit because the output responds immediately to the inputs and there is no memory. When memory is a part of a logic circuit，the system is called sequential circuit because its output depends on the input plus its an input signal isapplied.A bistable multivibrator，in the strict sense，is a flip-flop. When it is turned on，it assumes a particular operational state. It does not change states until the input is altered.A flip-flop opposite polarity.Two inputs are usually needed to alter the state of a flip-flop. A variety of names are used for the inputs.These vary a great deal between different flip-flops.1. R-S flip-flopsFig.3-5 shows logic circuit construction of an R-S flip-flop. It is constructed from two NAND gates. The output of each NAND provides one of the inputs for the other NAND. R stands for the reset input and S represents the set input.The truth table and logic symbol are shown in Fig. 3-6.Notice that the truth table is somewhat more complex than that of a gate. It shows, for example，the applied input, previous output，and resulting output.To understand the operation of an R-S flip-flop，we must first look at the previous outputs.This is the status of the output before a change is applied to the input. The first four items of the previous outputs are Q=1 and =0. The second four states this case of the input to NANDS is 0 and that is 0，which implies that both inputs to NANDR are 1.By symmetry，the logic circuit will also stable with Q0 and 1.If now R momentarily becomes 0，the output of NANDR，，will rise to resulting in NANDS be realized by a 0 at S.The outputs Q and are unpredictable when the inputs R and S are 0 states.This case is not allowed.Seldom would individual gates be used to construct a flip-flop，rather than one of the special types for the flip-flop packages on a single chipwould be used by a designer.A variety of different flip-flops are used in digital electronic systems today. In general，each flip-flop type R-S-T flip-flop for example .is a triggered R-S flip-flop. It will not change states when the R and S inputs assume a value until a trigger pulse is applied. This would permit a large number of flip-flops to change states all at the same time. Fig. 3-7 shows the logic circuit construction. The truth table and logic symbol are shown in Fig. 3-8. The R and S input are thus active when the signal at the gate input (T) is 1 .Normally，such timing，or synchronizing，signals are distributed throughout a digital system by clock pulses，as shown in Fig. 3-9.The symmetrical clock signal provides two times each period.The circuit can be designed to trigger at the leading or trailing edge of the clock. The logic symbols for edge trigger flip-flops are shown in Fig.3-10.2. J-K flip-flopsAnother very important flip-flop unpredictable output state. The J and K inputs addition to this，J-K flip-flops may employ preset and preclear functions. This is used to establish sequential timing operations. Fig.3-11 shows the logic symbol and truth table of a J-K flip-flop.3. 5. 2 CountersA flip-flop be used in switching operations，and it can count pulses.A series of interconnected flip-flops is generally called a register.Each register can store one binary digit or bit of data. Several flip-flops connected form a counter. Counting is a fundamental digital electronic function.For an electronic circuit to count，a number of things must beachieved. Basically，the circuit must be supplied with some form of data or information that is suitable for processing. Typically，electrical pulses that turn on and off are applied to the input of a counter. These pulses must initiate a state change in the circuit when they are received. The circuit must also be able to recognize where it is in counting sequence at any particular time. This requires some form of memory. The counter must also be able to respond to the next number in the sequence. In digital electronic systems flip-flops are primarily used to achieve counting. This type of device is capable of changing states when a pulse is applied，output pulse.There are several types of counters used in digital circuitry today.Probably the most common of these is the binary counter.This particular counter is designed to process two-state or binary information. J-K flip-flops are commonly used in binary counters.Refer now to the single J-K flip-flop of Fig. 3-11 .In its toggle state，this flip-flop is capable of achieving counting. First，assume that the flip-flop is in its reset state. This would cause Q to be 0 and Q to be 1 .Normally，we are concerned only with Q output in counting operations. The flip-flop is now connected for operation in the toggle mode. J and K must both be made the 1 state. When a pulse is applied to the T，or clock，input，Q changes to 1.This means that with one pulse applied，a 1 is generated in the output. The flip-flop the next pulse arrives，Q resets，or changes to 0. Essentially，this means that two input pulses produce only one output pulse. This is a divide-by-two function.For binary numbers，counting is achieved by a number of divide-by-two flip-flops.To count more than one pulse，additional flip-flops must be employed. For each flip-flop added to the counter，its capacity is increased by the power of 2. With one flip-flop the maximum count was 20，or 1 .For two flip-flops it would count two places，such as 20 and 21.This would reach a count of 3 or a binary number of 11.The count would be 00，01，10，and 11. The counter would then clear and return to 00. In effect, this counts four state changes. Three flip-flops would count three places，or 20，21，and 22.This would permit a total count of eight state changes.The binary values are 000，001，010，011，100，101，110 and 111.The maximum count is seven，or 111 .Four flip-flops would count four places，or 20，21，22，and 23.The total count would make 16 state changes. The maximum count would be 15，or the binary number 1111.Each additional flip-flop would cause this to increase one binary place.河南理工大学电气工程及其自动化专业中英双语对照翻译。
【精品毕设】机电专业论文英文文献及其中文译文
毕业论文外文文献翻译译文题目:INTEGRATION OF MACHINERY外文资料翻译资料来源：文章名：INTEGRATION OF MACHINERY 《Digital Image Processing》书刊名：作者：Y. Torres J. J. Pavón I. Nieto and J. A.Rodríguez章节：2.4 INTEGRATION OF MACHINERYINTEGRATION OF MACHINERY （From ELECTRICAL AND MACHINERY INDUSTRY）ABSTRACT Machinery was the modern science and technology development inevitable resultthis article has summarized the integration of machinery technology basic outlineand the development background .Summarized the domestic and foreign integration ofmachinery technology present situation has analyzed the integration of machinerytechnology trend of development. Key word：integration of machinery ，technology，present situation ，productt，echnique of manufacture ，trend of development 0. Introduction modern science and technology unceasing development impelleddifferent discipline intersecting enormously with the seepage has caused the projectdomain technological revolution and the transformation .In mechanical engineeringdomain because the microelectronic technology and the computer technology rapiddevelopment and forms to the mechanical industry seepage the integration of machinerycaused the mechanical industry the technical structure the product organizationthe function and the constitution the production method and the management systemhas had the huge change caused the industrial production to enter into quottheintegration of machineryquot by quotthe machinery electrificationquot for the characteristicdevelopment phase. 1. Integration of machinery outline integration of machinery is refers in theorganization new owner function the power function in the information processingfunction and the control function introduces the electronic technology unifies thesystem the mechanism and the computerization design and the software whichconstitutes always to call. The integration of machinery development also has becomeone to have until now own system new discipline not only develops along with thescience and technology but also entrusts with the new content .But its basiccharacteristic may summarize is: The integration of machinery is embarks from thesystem viewpoint synthesis community technologies and so on utilization mechanicaltechnology microelectronic technology automatic control technology computertechnology information technology sensing observation and control technologyelectric power electronic technology connection technology information conversiontechnology as well as software programming technology according to the systemfunction goal and the optimized organization goal reasonable disposition and thelayout various functions unit in multi-purpose high grade redundant reliable inthe low energy consumption significance realize the specific function value andcauses the overall system optimization the systems engineering technology .From thisproduces functional system then becomes an integration of machinery systematic orthe integration of machinery product. Therefore quotintegration of machineryquot coveringquottechnologyquot and quotproductquot two aspects .Only is the integration of machinerytechnology is based on the above community technology organic fusion one kind ofcomprehensivetechnology but is not mechanical technical the microelectronictechnology as well as other new technical simple combination pieces together .Thisis the integration of machinery and the machinery adds the machinery electrificationwhich the electricity forms in the concept basic difference .The mechanicalengineering technology has the merely technical to develop the machineryelectrification still was the traditional machinery its main function still wasreplaces with the enlargement physical strength .But after develops the integrationof machinery micro electron installment besides may substitute for certainmechanical parts the original function but also can entrust with many new functionslike the automatic detection the automatic reduction information demonstrate therecord the automatic control and the control automatic diagnosis and the protectionautomatically and so on .Not only namely the integration of machinery product ishumans hand and body extending humans sense organ and the brains look has theintellectualized characteristic is the integration of machinery and the machineryelectrification distinguishes in the function essence. 2. Integration of machinery development condition integration of machinerydevelopment may divide into 3 stages roughly.20th century 60s before for the firststage this stage is called the initial stage .In this time the people determinationnot on own initiative uses the electronic technology the preliminary achievement toconsummate the mechanical product the performance .Specially in Second World Warperiod the war has stimulated the mechanical product and the electronic technologyunion these mechanical and electrical union military technology postwar transferscivilly to postwar economical restoration positive function .Developed and thedevelopment at that time generally speaking also is at the spontaneouscondition .Because at that time the electronic technology development not yetachieved certain level mechanical technical and electronic technology union alsonot impossible widespread and thorough development already developed the productwas also unable to promote massively. The 20th century 7080 ages for the second stagemay be called the vigorous development stage .This time the computer technologythe control technology the communication development has laid the technology basefor the integration of machinery development . Large-scale ultra large scaleintegrated circuit and microcomputer swift and violent development has provided thefull material base for the integration of machinery development .This timecharacteristic is :①A mechatronics word first generally is accepted in Japanprobably obtains the quite widespread acknowledgment to 1980s last stages in theworldwide scale ②The integration of machinery technology and the product obtainedthe enormous development ③The various countries start to the integration ofmachinery technology and the product give the very big attention and the support.1990s later periods started the integration of machinery technology the new stagewhich makes great strides forward to the intellectualized direction the integrationof machinery enters the thorough development time .At the same time optics thecommunication and so on entered the integration of machinery processes thetechnology also zhan to appear tiny in the integration of machinery the footappeared the light integration of machinery and the micro integration of machineryand so on the new branch On the other hand to the integration ofmachinery systemmodeling design the analysis and the integrated method the integration ofmachinery discipline system and the trend of development has all conducted thethorough research .At the same time because the hugeprogress which domains and so on artificial intelligence technology neural networktechnology and optical fiber technology obtain opened the development vast worldfor the integration of machinery technology .These research will urge theintegration of machinery further to establish the integrity the foundation and formsthe integrity gradually the scientific system. Our country is only then starts fromthe beginning of 1980s in this aspect to study with the application .The State Councilhad been established the integration of machinery leading group and lists as quot863plansquot this technology .When formulated quot95quot the plan and in 2010 developed thesummary had considered fully on international the influence which and possiblybrought from this about the integration of machinery technology developmenttrend .Many universities colleges and institutes the development facility and somelarge and middle scale enterprises have done the massive work to this technicaldevelopment and the application does not yield certain result but and so on theadvanced countries compared with Japan still has the suitable disparity. 3. Integration of machinery trend of development integrations of machinery arethe collection machinery the electron optics the control the computer theinformation and so on the multi-disciplinary overlapping syntheses its developmentand the progress rely on and promote the correlation technology development and theprogress .Therefore the integration of machinery main development direction is asfollows: 3.1 Intellectualized intellectualizations are 21st century integration ofmachinery technological development important development directions .Theartificial intelligence obtains day by day in the integration of machineryconstructors research takes the robot and the numerical control engine bedintellectualization is the important application .Here said quottheintellectualizationquot is to the machine behavior description is in the control theoryfoundation the absorption artificial intelligence the operations research thecomputer science the fuzzy mathematics the psychology the physiology and the chaosdynamics and so on the new thought the new method simulate the human intelligenceenable it to have abilities and so on judgment inference logical thinkingindependent decision-making obtains the higher control goal in order to .Indeedenable the integration of machinery product to have with the human identicalintelligence is not impossible also is nonessential .But the high performancethe high speed microprocessor enable the integration of machinery product to havepreliminary intelligent or humans partial intelligences then is completelypossible and essential. In the modern manufacture process the information has become the controlmanufacture industry the determining factor moreover is the most active actuationfactor .Enhances the manufacture system information-handling capacity to become themodern manufacture science development a key point .As a result of the manufacturesystem information organization and structure multi-level makes the information thegain the integration and the fusion presents draws up the character informationmeasuremulti-dimensional as well as information organizations multi-level .In themanufacture information structural model manufacture information uniform restraintdissemination processing and magnanimous data aspects and so on manufacture knowledgelibrary management all also wait for further break through. Each kind of artificial intelligence tool and the computation intelligence methodpromoted the manufacture intelligence development in the manufacture widespreadapplication .A kind based on the biological evolution algorithm computationintelligent agent in includes thescheduling problem in the combination optimization solution area of technologyreceives the more and more universal attention hopefully completes the combinationoptimization question when the manufacture the solution speed and the solutionprecision aspect breaks through the question scale in pairs the restriction .Themanufacture intelligence also displays in: The intelligent dispatch the intelligentdesign the intelligent processing the robot study the intelligent control theintelligent craft plan the intelligent diagnosis and so on are various These question key breakthrough may form the product innovation the basicresearch system. Between 2 modern mechanical engineering front science differentscience overlapping fusion will have the new science accumulation the economicaldevelopment and societys progress has had the new request and the expectation tothe science and technology thus will form the front science .The front science alsohas solved and between the solution scientific question border area .The front sciencehas the obvious time domain the domain and the dynamic characteristic .The projectfront science distinguished in the general basic science important characteristicis it has covered the key science and technology question which the project actualappeared. Manufacture system is a complex large-scale system for satisfies the manufacturesystem agility the fast response and fast reorganization ability must profit fromthe information science the life sciences and the social sciences and so on themulti-disciplinary research results the exploration manufacture system newarchitecture the manufacture pattern and the manufacture system effectiveoperational mechanism .Makes the system optimization the organizational structureand the good movement condition is makes the system modeling the simulation andthe optimized essential target .Not only the manufacture system new architecture tomakes the enterprise the agility and may reorganize ability to the demand responseability to have the vital significance moreover to made the enterprise first floorproduction equipment the flexibility and may dynamic reorganization ability set ahigher request .The biological manufacture view more and more many is introduced themanufacture system satisfies the manufacture system new request. The study organizes and circulates method and technique of complicated systemfrom the biological phenomenon is a valid exit which will solve many hard nut tocracks that manufacturing industry face from now on currently .Imitating to livingwhat manufacturing point is mimicry living creature organ of from the organizationfrom match more from growth with from evolution etc. function structure and circulatemode of a kind of manufacturing system and manufacturing process. The manufacturing drives in the mechanism under continuously by ones ownperfect raise on organizing structure and circulating modeand thus to adapt theprocess ofwith ability for the environment .For from descend but the last productproceed together a design and make a craft rules the auto of the distance born producesystem of dynamic state reorganization and product and manufacturing the system tendautomatically excellent provided theories foundation and carry out acondition .Imitate to living a manufacturing to belong to manufacturing science andlife science ofquotthe far good luck is miscellaneous to hand overquot it will produceto the manufacturing industry for 21 centuries huge of influence .机电一体化摘要机电一体化是现代科学技术发展的必然结果本文简述了机电一体化技术的基本概要和发展背景。
同步电动机外文文献翻译中英文
外文文献翻译(含：英文原文及中文译文)英文原文Always magnetic belt synchro motor direct torque control system IntroductionSynchronous motors are widely used in industrial production due to their high power factor, high operating efficiency, good stability, and constant speed. Familiar with the starting failure of the synchronous motor and troubleshooting in time has important significance for the motor itself and the production system. In order to troubleshoot faults and handle faults in a timely and accurate manner, detailed analysis of common faults in synchronous motors must be performed.1 - Common Faults1.1 The synchronous motor cannot start after being energizedThere are generally several reasons why a synchronous motor cannot run after it is started:(1) The power supply voltage is too low. Since the starting torque of the synchronous motor is proportional to the square of the voltage, if the voltage of the power supply is too low, the starting torque of the synchronous motor will drop drastically and be lower than the load torque, thus failing to start. Therefore, the power supply voltage must be increased to increase the motor's power. Starting torque.(2) Failure of the motor itself Check the motor stator windings for short-circuit, open circuit, open-welding and poor connection. These faults will make the motor unable to establish the rated magnetic field strength, so that the motor can not start; check the motor Whether the bearing is damaged or not, if there is looseness of the end cap, if the bearing is damaged, the end cap loosens, the bearing sinks, and the stator core rubs, causing the motor to fail to start. If the rotor malfunctions, the low-pressure rocking table can be used to find the fault situation point by point. Take corresponding treatment methods; In the case of loose bearings and end caps, each time before driving, it is necessary to turn the car to see if the rotation of the motor rotor is flexible. If the bearing or the bearing bush is damaged, it must be replaced in time.(3) Failure of the control device. Such failures are mostly caused by improper adjustment or no output of the DC output voltage of the excitation winding, resulting in excessive stator current of the motor, resulting in over-current operation of the motor or loss of operation of the motor. At this point should check the excitation device output voltage and current waveform and whether it is normal, whether the fuse is blown, poor contact; circuit board plug is inserted firmly or aligned; check the loop resistance, the magnet thyristor is burned or broken down.(4) Mechanical failure. If the mechanical device being dragged gets stuck, causing the motor to fail to start, the rotor of the motor should beturned to see if the rotation is flexible and if the mechanical load is faulty.1.2 Synchronous motors cannot be brought into synchronization.Synchronous motor commonly used asynchronous starting method, in the motor rotor speed reached 95% synchronous speed when the excitation, so that it can be pulled into the synchronous synchronous motor can not pull into the following reasons:(1) The excitation winding is short-circuited. Due to the excitation winding, there is a short-circuit fault, so it is not possible to generate a rated magnetic field strength, resulting in that the motor can only operate stably below the synchronous speed and cannot be brought into synchronization. Look for a short circuit in the field winding. A low voltage (approximately 30 V) can be applied to the rotor lead-out. A manual hacksaw blade is placed on the pole face and the poles are checked one by one. If the hacksaw vibrates violently on the pole face, the pole is not Short-circuit, if the saw blade is vibrating or not vibrating, this pole is short-circuited and removed. After this magnetic pole, check the point of failure, which is the degree of short circuit, take partial repair or rewind.(2) The power supply voltage is too low. If the power supply voltage is too low, the strong excitation link of the excitation device cannot be operated, so that the motor cannot pull in synchronization. The specific method is to appropriately increase the power supply voltage.(3) Excitation device failure. If the excitation is too early (that is, when the excitation is applied, the rotor speed of the motor is too low), the motor cannot be brought into synchronization. At this time, it is necessary to check if there is a failure in the excitation section. If the excitation device is faulty and the output current is lower than the rated value, the electromagnetic torque of the motor is too small to pull in synchronization. At this time, the excitation and phase-shifting steps of the excitation device should be carefully checked, and the oscilloscope should be used to check the excitation. The waveform of phase-shifting phase should also check whether the degaussing thyristor is found to be normal or not, and deal with it in time. If it cannot be processed in time, the spare circuit board should be replaced in order to recover quickly.1.3 brushes and pressure springs, slip ring failure.Short brush and insufficient spring pressure cause poor contact between brush and slip ring, resulting in sparks or arcs. On the other hand, an arc or spark may cause short circuit, and on the other hand, the arc may be burnt shorter. Caused by open circuit, excitation device only excitation voltage and no excitation current; compression spring aging failure, making brush and slip ring contact is bad, thus affecting the start of the motor; collector ring surface with grease, streaks or groove marks This will cause poor contact between the brushes and the slip ring, causing sparks. The sparks will further burn the slip ring and cause ashort circuit to the ground, which will affect the starting of the motor. For the surface of the collector ring, grease can be scrubbed with acetone; for thin traces, sanding the ring repeatedly with sandpaper, the ring surface roughness R1.6um, such as groove marks obviously need to lathe processing, turning, cutting The quantity should be 1mm each time. When the turning speed is controlled at 1 -1.5m / s, the roughness reaches R1.5-1.8um, and the difference does not exceed 0.05mm. Finally it is polished 2-3 times with sandpaper.1.4 Damper winding failure.The damper winding of the synchronous motor rotor is used for starting the synchronous motor, and the out-of-step oscillation caused by the load change during operation is eliminated at the same time. In the process of starting the synchronous motor, the damper winding cuts the rotating magnetic field of the stator and induces a large starting current. Such a large current will inevitably cause the thermal expansion of the damper strip. Under normal circumstances, since the starting time is short, the damper winding will cool soon after being started. However, if the motor is stalled, the phase is missing, and the starting time is too long, failure to stop it in time will cause the stripping of the damper strip to be broken. The damper winding is a weak link in the synchronous motor components. Common faults in the damper winding Have:. Damping strip welding, fracture, discharge between the damping ring fire, severedeformation of the damping ring will affect the start of the synchronous motor. The damper strips are stripped, the silver-copper welding rods are used, and the gas welding is used. After the motor pulls the heart, the rotor is heated to 200 degrees Celsius in the oven. After removal, the rotor is placed vertically, and the welding temperature of 750 degrees Celsius is used to damp the strips and damping. All gaps between the rings are fully welded and then the welding slag is removed. For the broken damping strips, after removing the original damping strips, materials of the same material are selected. After the damping strips are installed, the welding method is used. Damping ring fire, mainly caused by poor contact between the damping ring or contact area is not enough. The deformation of the damping ring is mainly due to the fact that the damping strip is not fixed in the groove. In the welding, the damping strip is inserted into the damping ring hole. The additional stress after welding is caused by the insufficient strength of the damping ring. The treatment method is to loosen all the damping rings. Connecting bolts, for the deformation of the damping ring, heated by gas welding with a special fixture leveling, replacement of the new damping ring for serious deformation.2 example analysisExample 1 A synchronous motor uses an asynchronous starting method, but it is difficult to pull in the excitation current aftersynchronization.For the above situation, after shutdown, first check the power supply voltage is normal, and then use a multimeter and an oscilloscope to carefully check the excitation device, excitation voltage, current is normal, and finally is suspected of excitation winding short circuit. According to the method given in the previous paragraph, a low voltage (about 30V) can be applied to the rotor lead-out wire, a manual hacksaw blade is placed on the pole face, and the magnetic poles are inspected one by one, and it is found that the saw blade is slightly vibrated or not, indicating that the magnetic pole is short-circuited. After removing the magnetic pole, check with a rocker to confirm that the pole winding is short-circuited. After further inspection, it was found that the outer layers of the two layers were damaged by insulation. The coils were placed in an oven and heated to 150 degrees Celsius to soften the insulation between the turns. Gently pick up copper at the short-circuit and use 0.03 mm epoxy glass cloth. Pad into the board, then brush a layer of 1032 paint, placed in the oven by baking dry, and finally brush a layer of 183 insulating paint, install the magnetic pole. After the motor is assembled and started, it is synchronised smoothly.Example 2 When a synchronous motor was started at a certain factory, it was mechanically stuck and the start-up time was too long. It did not stop in time. When it was restarted, the damping ring wasdischarged. Some damping strips and damping rings are off for the above situation. Open the motor end box and check the reason why the damping ring is welded to small welding. The motor is divided into six-pole solid poles. Frequent starting due to heavy loads, damping strips have been used in the past and fractured. , Damping ring serious deformation failure, take repair welding, replace the broken damper, replace the damping ring and other measures. If the same treatment is used this time, the fault cannot be fully resolved. Considering that the damper ring has a monolithic structure, the large current flows through the heat and swells severely. However, when the solid magnetic pole is restarted, only the surface of the magnetic shoe heats up, the expansion is small, and the degree of expansion between the damper ring and the damper ring is different. Between the relative displacement and thermal stress, resulting in a serious deformation of the damping ring, such as off the welding failure. In order to overcome this defect, the damping ring is modified in this time. The damping ring is cut into 6-section fan-shaped rings. Drill holes at both ends of each ring to form a segmented damping ring. This eliminates the entire ring. The resulting internal stress and thermal stress.3 ConclusionWhen the synchronous motor fails, it is necessary to carefully analyze the possible causes and gradually eliminate it. If necessary, check the relevant materials, learn from experience, and propose improvementmeasures. Analysis of motor faults requires not only solid theoretical knowledge and extensive maintenance experience, but also specific failures, careful consideration, and courage to innovate to ensure that the fault-eliminated motor can operate stably for a long period of time.中文译文永磁同步电动机直接转矩控制系统引言同步电动机由于具有功率因数高，运行效率高，稳定性好，转速恒定等优点，被广泛应用于工业生产中。
电力专业英语 英文文献翻译报告
Page 1.The Production of Electrical Energy(电能生产)1 English textFrom reference 1Should the generation be not adequate to balance the load demand, it is imperative that one of following alternatives be considered for keeping the system in operating condition:1. Staring fast peaking units,2. Load shedding for unimportant loads,3. generation rescheduling.It is apparent from the above that since the voltage specifications are not stringent, load frequency control is by far the most important in power system control.In order to understand the frequency control, consider a small step-increase in load. The initial distribution of the load increment is determined by the system simpedance; and the sistantaneous relative generator rotor positions. The energy required to supply the load increment is drawn from the kinetic energy of rotating machines. As a result, the system frequency drops. The distribution of load during this period among the various machines is determined by the inertias of the rotors of the generators partaking in process. This problem is stability analysis of the system.After the speed or frequency fall due to reduction in stored energy in the rotors has taken place, the drop is sensed by the governors and they divide the load increment between the machines as determined by the droops of the respective governor characterstics. Subsequently, secondary control restores the system frequency to its normal value by readjusting the governor characteristics. Keywords：load frequency controlFrom reference 2Modern power systems are so large that it is impossible to design a single central control system that would handle the overall control job. It is extremely useful take into account the weak links in the system and then apply control throughdecomposition. The demarcation of load frequency control and Mavar voltage control characteristics is one such decomposition. Geographical and functional decomposition are successfully applied to power systems and this leads to the concept of area control.A modern power system can be divided into several areas for load frequency control. Each control area fulfils the following:1.The area is a geographically contious portion of a large interconnected area, which adjusts its own generation to accommodate load changes within its precincts.2.Under normal conditions of operation, it changes bulk power with neighboring areas.3.Under abnormal conditions of operation, it may deviate from predetermined schedules and provide assistance to any neighboring control area in the system.4.It is expected, in addition, to partake with the other areas in the system in a suitable manner in the system frequency regulation.The rotors of all generators in a control area swing together for load change. Thus, a coherent group of generators within a geographical region may constitute a control area which is connected to other similar areas by weak tie lines.Keywords：areas load frequency controlFrom reference 3For plant loading schedules in thermal systems, load prediction up to two hours in advance is necessary while for unit commitment schedules prediction up to 24 hours is sufficient. Also, at all sations and control centers, short-time prediction is needed for storage and display of advance information. Based on this information, predictive security assessment of the system is made. This also helps to contain the rates of change of generator outputs within their permissible limits.For the implementation of economic scheduling of generation using digital computers, detailed estimates of the future load demands are essential in order to allow sufficient time for the calculation and implementation of the generator schedules. Whatever method is envisaged for the calculation of such economic schedules consistent with the security and spare requirements of the system, the schedules should be calculatedevery 15 or 30 minutes and each economic schedule should be a predictive one ,for at least about 30 minutes ahead of event. It is then obvious that the predictions are to be revised frequently in the light of any fresh information so as to minimize the estimation errors.Peak load demand forecasts are useful in determining the investment required for additional generating and transmission capacities required. Forecasts for planning require data extending over several previous years. Meaningful forecasts can be obtained with lead time of 3 to 5 years.Keywords：load predictionFrom reference 4In this method, the load is separated into two main components. The first component is a base load which is of fixed value and the second a variable component which is a function of the weather conditions.Estimates can be made 24 hours ahead, using the weather forecast. The temperature base for weighting the effect of the predicated temperature on the load is the normal, mean temperature of the month. The normal, mean temperature of the month has zero weight. Similarly the change in consumers demand due to cloudy weather may be assumed to vary in direct proportion to the degree of cloudiness. This in turn may be expressed by an illumination index with fair, clear sky corresponding to zero weight.The base load is determined from past records. Proper weighting of the elements of the weather will be attained only after several trials. The method of prediction stabilizes after this trial period. It may be noted that the base loads for week days and weekend will generally be different for any hour.Using these base loads, a load estimate based on the best available weather forecast can be made using proper weighting of meteorological factors like temperature, cloudiness, wind velocity, etc.Keywords：proper weighting of the elements of the weather2 中文翻译及分析出自文献1：万一发电量不足以平衡负荷需求，要使电力系统处于运行状态，必须考虑采取以下选择方法中的一种：1、启动快速峰荷机组2、对不重要的用户实行拉闸断电3、重新制定发电计划从上述情况来看，电压技术的要求并不严格，目前为止负荷频率控制是电力系统控制中最重要的手段。
电机文献翻译
J. M.Hollerbach Dept. of Computer Science University of Utah Salt Lake City, UT 84112, USA
determine the phase currents of a variable-reluctance motor with respect to position and torque set points. Filicori et al. [4]proposed a dynamical torque controller based on a flux observer which minimizes copper losses or the maximum motor-feeding voltage. Le1 Huy et al. [lo, 3 reduces the torque ripple harmonics for brushless DC motor by using several drive current waveforms. The main tool in the control of synchronous motors is a transformation of phase currents via the ‘d-q transformation’ 191. Since this transformation linearizes only an ideal motor with perfectly sinusoidally distributed magneto-motive force, another torque set point is cascaded to cancel torque ripples. This method has been successfully implemented on the previous version of our McGill/MIT motor at MIT [7]. Less than f l N m ripple has been reported, however, in contrast to this paper, no attempt to minimize power dissipation was made. In a previous paper [I], we presented an alternative approach to torque ripple minimization, which was based on linear magnetics only. In contrast, the approach presented here is applicable to nonlinear magnetics as well. This paper is organized as follows: Section 2 presents an optimal nonlinear mapping (commutation law) from desired torque and position to motor phase angles with minimum copper losses. This mapping is available in closed form for linear magnetics. In Section 3, the experimental hydraulic dynamometer testbed is described, and the phase torque-angle and torque-current characteristics are identified experimentally for the McGill/MIT synchronous directdrive motor. The performance of the proposed commutation to produce virtually ripple-free torque and to yield precise position tracking is demonstrated in Section 4 experimentally.
电机学英文文献翻译
The three-phase induction motor speed control methodThree-phase asynchronous motor speed formula: N = 60f / p (1-s) Can be seen from the above formula, change the power supply frequency f, motor pole number p and the slip s may be too much to change the speed of purpose. From the speed of the essence of view, is simply a different way to change speed synchronous AC motor does not change the sync transfer speed or two.Widespread use in production machines without changing the synchronous speed of motor speed control method Wound Rotor Series Resistance Speed, chopper speed control, cascade control, and application of electromagnetic slip clutch, fluid couplings, clutches and other film speed. Change the synchronous speed of change on the number of stator pole multi-speed motor to change the stator voltage and frequency to frequency conversion with no change to the motor speed and so on.Energy from the speed point of view when, with high speed method and inefficient methods of two kinds of speed: high speed when the slip refers to the same, so no slip losses, such as multi-speed motors, Slip frequency control and loss can speed recovery methods (such as cascade control, etc.). A deteriorating loss of speed control methods are inefficient speed, such as series resistance of the rotor speed method, the energy loss in the rotor circuit on; Electromagnetic Clutch The speed method, the energy loss in the clutch coils; fluid coupling speed, energy loss in the fluid coupling of the oil. General deterioration in loss increased with the expansion speed range, if not speed range, the energy loss is minimal.1, variable speed control method of pole pairsThis speed is then used to change the stator winding way to change the red cage motor stator pole pairs to achieve speed control purposes, the followingfeaturesWith hard mechanical properties, good stability;No slip loss, high efficiency; Wiring simple, easy to control, low price;A level speed, differential large, can not get smooth speed control;With pressure and speed adjustment, with the use of electromagnetic slip clutch,smooth and efficient access to high speed characteristics.This method is suitable for the production does not require variable speed machinery, such as metal cutting machine Bed , Lift , Lifting equipment, Fans Water Pump And so on.2, Frequency Control Method Frequency control is to change the motor stator Power supply Frequency, thus changing the speed of its synchronous speed method. Frequency control system main equipment is to provide variable frequency power supply Inverter , Inverter can be divided into AC - DC - AC inverter and AC - AC converter two categories, most of the current domestic use of AC - DC - AC inverter. Its characteristicsHighefficiency, speed the process without additional loss;Wide range of applications, can be used for cage induction motor;Speed range, features a hard, high accuracy;Technical complexity, high cost, difficult maintenance and overhaul.This method is suitable for the high accuracy, good speed performance occasions.3, cascade control method Cascade control is wound into the rotor circuit in the series of additional potential can be adjusted to change the motor's slip, to achieve speed control purposes. Most of the deterioration in power to be in series with the added potential absorbed, re-use generate additional devices to absorb the deterioration in power to return power to use or conversion of energy. Slip-power absorption under way, cascade control can be divided into Motor Cascade control, mechanical and thyristor cascade control cascade control, and multi-use cascade control thyristor, characterized byCan speed the process of deterioration in loss of feedback to the network or productionmachinery, more efficient;Installed capacity and speed range in direct proportion to investment, applicable speed range 70% -90% rated speed of production machinery;peed device failure can switch to full speed, to avoid the cut-off;Thyristor cascade speed low power factor, harmonics greater impact.This method is suitable for fans, pumps and rolling mills, mine hoist, extrusion machines.4, wound rotor motor speed control method of Series ResistanceWound Rotor Motor additional resistance in series, so that the motor slip up, motor running at low speed. The greater the resistance in series, the motor speed is lower. This method is simple, easy to control, but deteriorate the power consumption in the form of heat in the resistor. Is a class speed, soft mechanical properties.5, the stator pressure and speed adjustment methodStator voltage when changing the motor, you can get a different set of mechanical properties of curves, which were different speeds. Since the motor torque and voltage proportional to the square, the largest decline in a lot of torque, speed range of its small cage motors in general and difficult to apply. In order to expand the speed range, pressure and speed adjustment should be larger rotor resistance value cage motors, such as dedicated voltage regulator with speed torque motor, or series wound motor frequency sensitive resistors. In order to expand the range of stable operation, when the speed of 2:1 or more occasions in the feedback control should be adopted to achieve the purpose of automatic adjustment of speed.Pressure and speed adjustment is a key device to provide power supply voltage, the current way of a tandem common saturation voltage regulator Reactor , Auto Transformer And several other Thyristor Surge. Thyristor Surge is the best way. Adjusting Speed featuresPressure and speed adjustment circuit is simple, easy to realize automatic control;Poor power surge process to heat transfer in the rotor resistance in the form of consumption, low efficiency.Pressure and speed adjustment generally applies to 100KW below production machinery.6.electromagnetic speed regulating motor speed control method of electromagneticspeed regulating electric motor squirrel cage motor, electric slip clutch and DC excitation power supply (Controller) consists of three parts. DC excitation power small, usually consisting of single phase half-wave or full wave rectifiers thyristors composition, change thyristor conduction angle, you can change the magnetizing current size.Electromagnetic slip clutch armature, poles and excitation windings composed of three parts. Armature and the latter has no mechanical contact, are free to rotate. Armature motor coaxial connection active part, driven by motors; docking with the load axis magnetic pole coupling from the moving parts. When the armature poles are at rest, such as excitation windings for DC, along the circumferential surface will form a number of air gap on the n, s, of alternating polarity poles, the magnetic flux through the armature. Dang electric armature with drag motor rotating Shi, due to electric armature and pole between relative movement, and makes electric armature induction produced Eddy, this Eddy and magnetic pass mutual role produced go moments, led has pole of rotor by same direction rotating, but its speed constant below electric armature of speed N1, this is a go difference adjustable speed way, changes go difference clutch device of DC Lai magnetic current, will can change clutch device of output go moments and speed. Characteristics of electromagnetic speed regulating motor speed:appliances, structure and control circuit is simple, reliable operation, easymaintenance; speed and smooth, stepless speed regulationthe power network harmonic effects;lost speed, low efficiency.This method applies to medium and small power, requires low speed when the smooth, short run production machinery.7. the hydraulic coupler speed regulating hydraulic Coupler is a device for hydraulic drive, is made up of the pump and turbine, they collectively work wheels, placed in a sealed case. Shell filled with a certain amount of working fluid, when pump is impulse driven by rotation, in which liquid propelled by blades which rotate, and under the action of centrifugal force along the outer wheels when entering the turbine pump, to thrust to the turbine blades on the same turn, make it drive production machinery running. Power transfer capacity of the hydraulic coupler and shell filled with fluid volume sizes are consistent. In the course of work, changing the filling rate can change the coupler of turbine speed, stepless speed regulation, characterized by:power scope, can meet the needs of from a couple of different power 10-kilowattto shuqianqian;simple structure, reliable performance, easy to operation and maintenance, andlow cost;small size, capacity;easy to adjust, easy to fulfill automatic control.This method applies to the speed of the fan and water pump.三相异步电动机的几种调速方式三相异步电动机转速公式为：n=60f/p(1-s)从上式可见，改变供电频率f、电动机的极对数p及转差率s均可太到改变转速的目的。
电动机控制中英文对照外文翻译文献
电动机控制中英文对照外文翻译文献(文档含英文原文和中文翻译)原文：Control of Electric winchFor motor control, we know the best way is to use the style buttons to move the many simple manual console. And this console, in some applications may still be a good choice, as some complex control headache can also be used. This article describes in your design, build or purchase winch controller, you have the motor's basic electrical equipment and you will need to address the user interface command addressed.First, the manual should be a manual control console type, so if you remove your finger buttons, hoist will stop. In addition, each control station equipped with an emergency need to brake, hoist the emergency brake to cut off all power, not just the control circuit. Think about it, if the hoist at the stop, it did not stop, you do need a way to cut off the fault line protection power. Set the table in the control of a key operated switch, is also a very good idea, especially in the line leading to theworkstation can not control, you can use the switch.(in the design of the console, even the simplest manual console, but also consider setting by specialized personnel to operate the safe operation of the keys.) Constant speed motor controlFor a fixed speed winch actual control device is a three-phase starter. Turn the motor is reversed, by a simple switch controlled phase transformation sequence from ABC to CBA. These actions are completed by two three-pole contactor-style, and they are interlocked, so that they can not be simultaneously closed. NEC, required in addition to overload and short circuit protection devices. To protect the motor against overload due to mechanical effects caused by overheating in the heat to be installed inside the starter overload delay device. When the heat overload delay device overheating, it has a long double off the metal motor power. In addition In addition, you can also select a thermistor can be installed in the motor winding way, it can be used to monitor motor temperature changes. For the short-circuit protection, we generally used by motor fuses to achieve.A linear current independent contactors, the contactors are configured should be more than the current main circuit contactor, so as to achieve the purpose of redundancy. This sets the current contactor is controlled by the security circuit, such as: emergency brake and the more-way limits.We can use the limit switches to achieve the above operation. When you reach the end of the normal travel limit position, the hoist will stop, and you can only move the winch in the opposite direction (ie, the direction away from the limit position.) There is also need for a more limited way just in case, due to electrical or mechanical problems, leaving the operation of hoist limit bit more than normal. If you run into more limiter, linear contactor will open, therefore, can not be driven winch will exceed this limit position. If this happens, you need to ask a professional technician to check the lead to meet the more specific reasons limiter. Then, you can use thestarter toggle switch inside the elastic recovery process to deal with more problems, rather than tripping device or a hand-off the current contacts.A necessary condition for speedOf course, the simple fixed speed starter is replaced by variable speed drives. This makes things start to get interesting again! At a minimum, you need to add a speed control dial operation platform. Joystick is a better user interface, because it makes you move parts of a more intuitive control.Unfortunately, you can not just from your local console to send commands to control the old variable speed drives, in addition, you can not want it in the initial stages, will be able to enhance the safe and reliable and decentralized facilities. Most of the variable speed drive can not achieve these requirements, because they are not designed to do upgrading work. Drivers need to be set to release the brake before the motor can generate torque, and when parking, that is, before the revocation of torque, the brake will be the first action.For many years, DC motors and drives provide a number of common solutions, such as when they are in a variety of speeds with good torque characteristics. For most of the hoist of the large demand for DC motor is very expensive, and that the same type of AC motor than the much more expensive. Although the early AC drives are not very useful, as they have a very limited scope of application of the speed, but produced only a small low-speed torque. Now, with the DC drives the development of low cost and a large number of available AC motors has led to a communication-driven revolution.Variable speed AC drives in two series. Frequency converter has been widely known and, indeed, easy to use. These drives convert AC into DC, and then, and then convert it back to exchange, the exchange after the conversion is a different frequency. If the drive produced the exchange of 30Hz, 60Hz a normal motor will run at half speed. Theoretically, this is very good, but in practice, this will have a lot of problems. First of all, a typical linear motor 60Hz frequencies below 2Hz 3Hz area or there will be errors, and start cog (that urgent push, yank), or parking. This will limit your speed range lower than 20:1, almost not adapted to the operational phase of the fine adjustment. Second, many low-cost converter is not able to provide the rated torque at low speeds. Use of these drives, will result in the rapid move to upgrade the components or complete failure, precisely, when you try to upgrade a stable scientific instruments, you do not want to see this situation. Some new inverter is a closed-loop system (to get feedback from the motor to provide a more accurate speed control), and the motor will work quite well.Another series of AC drives is the flow vector type drive. These components require installation of the spindle motor encoder, encoder makes use of these drivescan accurately monitor the rotation of the motor armature. Processor accurately measured magnetic flux vector values that are required to make the armature at a given speed rotation. These drives allow infinite speed, so you actually can produce at zero speed to rated torque. These drives provide precise speed and position control, so these drives in high performance applications to be welcomed.(Based on PLC controllers provide system status and control options. This screen shows the operator full access to the nine-story elevator enhance the control panel.) PLC-based systemsIs the full name of a PLC programmable logic controller. First of all, PLC controller developed to replace the fifties and sixties-based industrial control system relay, they work in harsh industrial indoor environments. These are modular systems that have a large variety of I / O modules. The modular system can easily achieve the semi-custom hardware configuration assembled, and the resulting configuration is also very reasonable price. These modules include: position control module, the counter, A / D and D / A converter, and a variety of physical state or physical contact with closed output module. Large number of different types of I / O components and PLC module property makes it an effective way to assemble custom and semi custom control system.The biggest shortcoming of PLC systems is the lack of the real number of display to tell you what is being done and the PLC on the PLC program to help you.T he first is professional entertainment for the large-scale PLC system is one of the original in Las Vegas, MGM (now Bailey Company) of the riding and carriage system. Many manufacturers offer a standard PLC-based semi-automated acoustic systems and a host of signs, set the location of the command line interpreter, and the upgrading of the control system is also available. Using standard modules to set user-defined system configuration capability is based on the PLC controller of the greatest advantage.High-end controllerFor complex transmission, the controller became complex, more than speed, time and location control. They include complex instructions to write and record the movement contour, and the processing can immediately run the ability to multi-point instructions.Many large opera house is toward the direction of point lift system, where each one is equipped with a rope to enhance independent winches, rope equivalent to those of each dimmer circuit. When more than one hoist is used to enhance the individual part, the hoist must be fully synchronous, or the load to shift, so will lead to a separate winch becomes the risk of overload. Control system must be able to be selected to keep pace winch, or a hoist winch is not able to maintain synchronization with the other, can provide the same high-speed parking capacity. For a typical speed of 240 ft / min and a winch to maintain the rate of error of between 1 / 8 points of equipment, you only have less than three microseconds of time to identify problems and try to correct the error The hoist speed, make sure you fail, you start all the winch stop the group. This will require a large amount of computation, fast I / O interface, and easy to use to write software.For large rope control system has two very different solutions. The first is to use a separate console, the problem in general terms, this console should be installed in the appropriate location of the operator perspective. However, this not only from one angle to another angle, but still can not get an instruction to another instruction from the control. These difficulties have been partially resolved. Installed in different locations through the use of video cameras, and these cameras connected to the three-dimensional display graphics, these graphics enables the operator to observe from the perspective of any of the three coordinates in the expected direction of rope movement. These operators can make from a console for him at the actual angle, or closed circuit camera practical perspective, to observe the movement of the rope on the screen. For the complex interrelated moving parts, makes the implementation of the above observation Failure to control and find out easier.Another solution to the problem is a distributed system that uses multiple light console. This will allow the different operators in the same way the different aspects of control gear, we have improved the manual control device. A vivid example is the flower in a vegetable market in central London, the Royal Opera House, the program uses the above, where the control console 240 with ten motors. Each console has five playback device, and has been open, so that each motor has been assigned to a single console. An operator and a console can control all the devices, however, often may be running a console platform screen upgrade, another console is a console on the transmission device, and the third console is used to the necessary backgroundin the background image down.(edge-type portable console allows the operator many advantages from the start to control the movement of the machine, and provide three-dimensional image display.)ConclusionA huge change in the rope control system, a workstation has been developed from a push-button to complex multi-user computerized control system. When the control system to buy rope, you can always find to meet your needs. Control system performance is the most important security and reliability. These are the true value of the property, and you can expect the price to buy a suitable way of security. With a certain product manufacturers to work, he will make you know how to install it. And he will make contact with you and the users, those users have with similar requests.译文：电动卷扬机的控制对于电动机的控制，我们所知道的最好的方式就是使用由许多点动式按钮组成的简单的手工操作台。
电机学专外原文和翻译
Introduction to D.C MachinesA D.C machines is made up of two basic components:－The stator which is the stationary part of the machine. It consists of the following elements: a yoke inside a frame; excitation poles and winding; commutating poles (composes) and winding; end shield with ball or sliding bearings; brushes and brush holders; the terminal box.－The rotor which is the moving part of the machine. It is made up of a core mounted on the machine shaft. This core has uniformly spaced slots into which the armature winding is fitted. A commutator, and often a fan, is also located on the machine shaft.The frame is fixed to the floor by means of a bedplate and bolts. On low power machines the frame and yoke are one and the same components, through which the magnetic flux produced by the excitation poles closes. The frame and yoke are built of cast iron or cast steel or sometimes from welded steel plates.In low-power and controlled rectifier-supplied machines the yoke is built up of thin (0.5～1mm) laminated iron sheets. The yoke is usually mounted inside a non-ferromagnetic frame (usually made of aluminum alloys, to keep down the weight). To either side of the frame there are bolted two end shields, which contain the ball or sliding bearings.The (main)excitation poles are built from 0.5～1mm iron sheets held together by riveted bolts. The poles are fixed into the frame by means of bolts. They support the windings carrying the excitation current.On the rotor side, at the end of the pole core is the so-called pole-shoe that is meant to facilitate a given distribution of the magnetic flux through the air gap. The winding is placed inside an insulated frame mounted on the core, and secured by the pole-shoe.The excitation windings are made of insulated round or rectangular conductors, and are connected either in series or in parallel. The windings are liked in such a way that the magnetic flux of one pole crossing the air gap is directed from the pole-shoe towards the armature (North Pole), which the flux of the next pole is directed from the armature to the pole-shoe (South Pole).The commutating poles, like the main poles, consist of a core ending in the pole-shoe and a winding wound round the core. They are located on the symmetry (neutral) axis between two main poles, and bolted on the yoke. Commutating poles are built either of cast-iron or iron sheets.The windings of the commutating poles are also made from insulated round or rectangular conductors. They are connected either in series or in parallel and carry the machine's main current.The rotor core is built of 0.5～1mm silicon-alloy sheets. The sheets are insulated from one another by a thin film of varnish or by an oxide coating. Both some 0.03～0.05mm thick. The purpose is to ensure a reduction of the eddy currents that arise in the core when it rotates inside the magnetic field. These currents cause energy losses that turn into heat. In solid cores, these losses could become very high, reducing machine efficiency and producing intense heating.The rotor core consists of a few packets of metal sheet. Redial or axial cooling ducts (8～10mm inside) are inserted between the packets to give better cooling. Pressure is exerted to both side of the core by pressing devices foxed on to the shaft. The length of the rotor usually exceeds that of the poles by 2～5mm on either side－the effect being to minimize the variations in magnetic permeability caused by axial armature displacement. The periphery of the rotor is provided with teeth and slots into which the armature winding is inserted.The rotor winding consists either of coils wound directly in the rotor slots by means of specially designed machines or coils already formed. The winding is carefully insulated, and it secured within the slots by means of wedges made of wood or other insulating material.The winding overcharge are bent over and tied to one another with steel wire in order to resist the deformation that could be caused by the centrifugal force.The coil-junctions of the rotor winding are connected to the commutator mounted on the armature shaft. The commutator is cylinder made of small copper. Segments insulated from one another, and also from the clamping elements by a layer of minacity. The ends of the rotor coil are soldered to each segment.On low-power machines, the commutator segments form a single unit, insulated from one another by means of a synthetic resin such as Bakelite.To link the armature winding to fixed machine terminals, a set of carbon brushes slide on the commutator surface by means of brush holders. The brushes contact the commutator segments with a constant pressure ensured by a spring and lever. Clamps mounted on the end shields support the brush holders.The brushes are connected electrically－with the odd-numbered brushes connected to one terminal of the machine and the even-numbered brushes to the other. The brushes are equally spaced round the periphery of the commutator－the number of rows of brushes being equal to the number of excitation poles.直流电机的介绍一个直流电机是由两个基本元素组成：－定子是电机固定的部分。
电机专业英语全
电机专业英语全电机专业英语电机electric engine; electric machine; electric (al) motor电机参数parameter of electric machine电机槽宽tooth ratio电机槽内导体electric machine slot-conductor电机常数constant of the machine电机厂motormaker电机车haulage motor电机车架空线保护trolley wire guard电机车运输electric(al) haulage电机传动辊motorised roll电机传动轴motor transmission shaft电机磁场motor-field电机的电气线端electric terminals of a machine电机的规格rating of machine电机的输入功率power input to a machine电机的铁间空隙entrefer电机底座motor base电机电刷motor brush电机调整器regulator generator电机定子铁芯自动焊接机dynamo stator core automatic welder 电机端部磁场end-region magnetic field of electrical machine 电机短路测试仪electric motor short circuit test instrument电机放大器amplidyne generator; motor amplifier; rotating amplifier 电机放大器控制部件amplidyne control unit电机放大器伺服系统amplidyne servomechanism电机放大伺服机构amplidyne servomechanism电机钢dynamo steel电机钢板dynamo steel sheet电机工程electric engineering电机工程师electrical engineer电机功率power of motor电机规格rating of machine电机硅钢片dynamo sheet电机黄铜合金motor brass alloy电机减速机motor reducer; motor reducing gear电机壳motor casing; motor enclosure电机控制electric machine control电机控制器machine controller电机偏心率motor eccentricity电机起动器motor starter电机青铜dynamo bronze电机驱动motor drive电机驱动的motor-driven电机驱动开关motor driven switch电机驱动种子清选机motor-driven seed cleaner电机绕组machine winding电机设计electric machine design电机室motor room电机输送motor transport电机数量number of motors电机损耗loss of machine电机碳刷carbon brush for electric machine; motor carbon 电机效率electric efficiency; electrical efficiency电机械加工electromechanical working电机械模拟electromechanical analogy电机学electromechanics电机用薄钢片dynamo sheet steel电机用硅钢片dynamo steel sheet电机用油motor oil电机油dynamo oil; electric engine oil电机运行特性electric machine operating characteristic电机制造业electric manufacturing电机轴motor shaft电机轴承motor bearings电机转子试验装置motor rotor tester电机转子压铸机die-casting machine for motor rotor电机自动继电器motor automatic relay电机座motor cabinet电机座位motor cavity3-phase slip-ring induction motor 三相滑环式感应电动机3-phase squirrel cage induction motor 三相鼠笼式感应电动机battery-operated motor cycle (玩具) 电动摩托车bearing of motor 电动机轴承bin drive motor 分页格驱动电机biphase motor 两相电动机bisynchronous motor 双倍同步速度电动机blower motor 鼓风电动机; 鼓风机用马达boost motor 助推器; 加速器Boucherot (squirrel-cage) motor 双鼠笼式电动机box-frame motor 箱形机座电动机; 框形电动机brake motor 制动电动机brush and slotless motor 无电刷槽电动机brush motor 换向器电动机; 整流式电动机brush-shifting motor 移刷型电动机built-in motor 机内电动机built-in motor drive 单独电机传动; 单独内装电机传动cagemotor 鼠笼式电动机cam-type axial piston motor 斜盘式轴向柱塞电动机canned motor 封闭电动机; 密封式发动机canned motor pump 密封电动泵; 密封式电动泵; 屏蔽泵capacitive motor 电容电动机capacitor induction motor 电容电动机capacitor motor 电容起动电动机; 电容器起动电动机; 电容式单相电动机; 电容式电动机capacitor split-phase motor 电容分相式电动机capacitor start and run motor 电容起动行驶式电动机capacitor start motor 电容起动电动机capacitor start-run motor 固定分相电容器式电动机capacitor-start motor 电容器起动电动机; 电容式启动电动机capacitor-start-and-run motor 电容式启动和运转的电动机capstan motor 主导电动机; 主动轮电动机cascade motor 级联电动机cascade motors 级联电动机组ceiling-fan motor 吊扇电机cell motor 电池电动机centre drvie motor mower 中央驱动动力割草机ceramic permanent-magnet motor 陶瓷永磁电动机; 铁淦氧永磁电动机chain-drive motorcycle 链动机器脚踏车chain-type side-rake for motormower 动力割草机的链指式侧向搂草器change speed motor 分级调速式电动机change-speed motor 变速电动机charge motor 充电马达; 充电用电动机chopper motor 斩波器供电电动机; 断路电动机Class I Motor Carrier 一级汽车运输公司clock motor 计时电动机; 电钟用电动机close-ratio two-speed motor 近比率双速电动机closing motor 密闭电动机clutch motor 带离合器电动机coastal motor boat 海岸汽船coller for motor 电动机冷却器combustion motor 内燃机commercial motor 商用电动机common pumpl motor base 泵与电动机的共用底座commutating pole motor 换向极电动机commutator induction motor 换向器感应电动机commutator motor 换向器式电动机; 整流式电动机; 整流子式电动机commutator variable speed motor 换向器变速电动机compass torque motor 罗盘矫正电动机compensated commutator motor 补偿整流电动机compensated induction motor 补偿感应电动机; 补偿式感应电动机compensated motor 补偿电动机compensated repulsion motor 补偿感应推斥电动机; 补偿式推斥电动机; 补偿推斥电动机; 补偿推斥式电动机compensated series motor 补偿串激式电动机; 补偿串励电动机complete motor type 配带电机型号compound motor 复励电动机compound-wound motor 复激电动机; 复励电动机compressed air motor 气动电动机concatenated motor 级联电动机; 链系电动机; 串级电动机concatenation motor 链系电动机; 串级电动机condenser motor 电容式电动机condenser run motor 电容起动电动机condenser shunt type induction motor 电容分相式感应电动机condenser start motor 电容起动电动机condenser-start induction motor 电容起动感应电动机connector motor magnet 回转电磁铁consequent-poles motor 变极式双速电动机; 交替磁极式电动机constant current motor 定流电动机constant displacement motor 定量马达constant field commutator motor 定激励整流式电动机constant power motor 恒定功率电动机constant pressure motor 等压内燃机constant speed motor 等速电动机; 恒速电动机; 定速电动机constant torque asynchronous motor 恒力矩异步电动机constant voltage motor 恒压电动机; 定电压电动机constant voltage motor generator 恒压电动机发电机constant-current motor 恒流电动机constant-speed motor 等速马达constant-voltage motor 恒定电压电动机continuous-time-rated motor 连续运行电动机continuously rated motor 连续额定运行电动机converter-fed motor 换流器供电电动机coolant pump motor 冷却液泵电动机cooled motor 冷却式发动机cortical motor area 皮层运动区cortical motor areas 皮质运动区crane motor 吊车电动机crawler-type motor grader 履带式自动平地机crescent gear motor 内啮合齿轮马达cross feed motor 交叉馈电式电动机cumulative compound motor 积复激电动机cup motor 杯形电机current-displacement motor 深槽电动机; 深槽感应电动机cutter motor 截煤机电动机cycloid gear hydraulic motor 摆线齿轮油液压马达cycloidal gear reducing motor 摆线齿轮减速电动机cycloidal needle wheel type motor 摆线针轮电动机DC electronic motor 离子式直流电动机DC series motor 串激直流电动机dead motor 关闭的电动机decompounded motor 差复励电动机decussation motoria 运动交叉deep-bar motor 深槽鼠笼式电动机deep-slot induction motor 深槽感应电动机deep-slot motor 深槽感应电动机deep-slot squirrel cage motor 深槽鼠笼式电动机definite-purpose motor 专用电动机deluge proof motor 防水电动机Denison motor 丹尼森液压电动机; 轴向回转柱塞式液压电动机Deri motor 德里电动机Deri repulsion motor 德里推斥电动机despun motor 反旋转电动机; 反自转电动机diaphragm motor 膜片阀控制电动机; 光阑驱动电动机die-casting machine for motor rotor 电机转子压铸机diesel motor 狄塞尔发动机diesel motor roller 柴油碾压机; 柴油压路机differential compound motor 差复激电动机; 差复励电动机; 差复励电视机; 差复绕电动机; 差绕复激电动机differential motor 差绕电动机differential selsyn motor 差动自动同步电机differential shunt motor 差并励电动机differential wound motor 差励电动机differential-field motor 他激差绕直流电动机differential-field series motor 串激差绕直流电动机differentially-compound wound motor 差复激电动机differentially-wound motor 差绕电动机direct motor drive 电动机直接传动direct motor driven 单电动机传动的direct-connected motor 直连电动机direct-coupling motor converter 连轴电动换流机direct-current motor control 电动机电子控制direct-motor-driven 单电动机传动disabled motor switch 电动机故障断路器dither motor 高频振动电动机; 高频振动电机; 高频振动用电动机double armature motor 双电枢电动机double commutator motor 双整流子电动机; 双换向器电动机double motor 双电动机double squirrelcage motor 双鼠笼电动机double-casing motor 双层机壳式电机double-fed repulsion motor 双馈推斥电动机double-reduction motor 两级减速电动机double-unit motor 双电动机机组drag-cup induction motor 空心转子感应电动机drag-cup motor 拖杯式电动机; 托杯形电动机drag-cup type rotor motor 空心转子电动机drill-motor rotor vane 钻孔转子叶片drip-proof motor 防滴式电动机drip-proof type induction motor 防滴式感应电动机drive motor 传动马达driver motor 主驱动电动机driving shaft motor 传动轴电机drop-proof type motor 防滴水式电动机drum motor 鼓形电动机dual-capacitor motor 双电容器式电动机dual-frequency motor 双频率电动机dual-thrust motor 双推力发动机duocentric motor 同心双转子电动机duplex power feed type A.C. commutator motor 并联馈电整流式交流电动机dust-tight type motor 防尘式电动机dynamoelectric motor 旋转换流机E-P signal motor 电动气动信号机eddy currents in attraction type motor 吸引型电动机中的涡流eddy-current motor 涡流电动机either-rotation motor 双向电机electric (al) motor 电机electric hoist with creep lifting motor 变速电葫芦electric motor 电动机electric motor car 电动车; 电动机车electric motor coach 电动客车electric motor drive 电动机传动electric motor driven butter churn 电动乳脂制作器electric motor for rolling way 辊道电动机electric motor generator 电动发电机electric motor movie camera 电动式活动摄影机electric motor oil 电动机油electric motor saw 电锯; 电力锯electric motor short circuit test instrument 电机短路测试仪electric motor signal mechanism 电动臂板信号机构electric motor truck 电气载重车electric motor-drawn channel scraper 电动粪槽刮铲electric motor-operated fixed crane 固定式电动起重机electric motordriven point mechanism 电动转辙机构electric pulse motor电脉冲电动机electric starter motor 电力起动机electric vehicle motor 牵引电动机electric wiper motor 刮水器电动机electrical motor 电动机electrically operated motor car 电动车electro-hydraulic servo motor 电动液压伺服电动机electro-motor 电动马达electrohydraulic stepping motor 电液步进马达electromagnetic speed-adjustable motor 电磁调速电动机electromagnetic variable-speed motor 电磁调速电动机electronic motor control 电动机电子控制electronic motor controller 电子电动机控制器electropneumatic point motor 电动气动转辙机electropneumatic signal motor 电动气动信号机electrostatic motor 静电电动机; 静电电动机elevating motor 升降电动机elevation drive motor 仰角传动电动机; 仰角驱动电动机enclosed motor 密封式电动机; 封闭电动机; 封闭式电动机; 封闭型电动机enclosed type induction motor 封闭式感应电动机enclosed type motor 封闭式电动机enclosed ventilated motor 封闭通风式电动机engine cranking motor 发动机起动马达Enor motor 埃诺罗式叶片液压马达epicycle motor 行星减速电动机erection torque motor 竖起力矩电动机; 架设转矩电动机exciter motor-generator 励磁电动发电机expiratory motor neuron 呼气运动神经元explosion motor 爆燃式发动机explosion-proof motor 防爆马达; 防爆型电机explosion-proof type induction motor 防爆式感应电动机explosion-proof ventilated synchronous motor 防爆通风型同步电动机explosive motor 内燃发动机external concrete vibrators with motor 带电动机的混凝土振动器external-rotor motor 外转子式电动机externally reversible motor 双向启动可逆电动机face-type motor 凸缘型电动机fan motor 风扇电动机; 风扇马达fan-cooled motor 全封密风冷式电动机farm motor 农用电动机feed motor 进给电动机Ferrari s motor 费拉里电动机field-control motor 磁场可控式电动机; 可调磁场型电动机fixed brush type polyphase series motor 固定电刷式多相串激电动机fixed displacement motor 定量马达fixed-displacement motor 定容量马达flame-proof 3-phase induction motor 防爆型三相感应电动机flame-proof electric motor 防爆电动机flame-proof motor 防爆式电动机flange motor 凸缘底座电动机; 凸缘型电动机flange-mounted motor 凸缘型电动机flange-type motor 凸缘型电动机; 法兰式电动机flanged motor 凸缘电动机flea-size motor 超小型电动机fluid motor 液力发动机; 液压马达fluid power motor 液压发动机fluid pressure motor 液压电动机fluid servo-motor 液压伺服马达fluid-power motor 液力电动机; 液力马达fluidic stepping motor 射流式步进电动机follower motor 随动电动机foot engine with electric motor 牙科脚踏电动二用钻机foot-mounted motor 底座安装型电动机; 落地安装型电动机force motor 执行电动机forced-ventilated motor 强制通风式电动机form-wound motorette 模绕线圈试验装置foundation bolt for motor 电动机地脚螺栓four-phase stepper motor 四相步进电动机four-pole motor 四极电动机four-stroke motor 四冲程发动机four-wheel motor vehicle 四轮机动车辆fractional electric motor 小功率电动机; 分马力电动机fractional horse power motor 分数马力电动机fractional horse-power motor 分数功率电动机fractional horsepower motor 分马力电动机fractional HP light metal induction motors 铝合金壳分马力感应电动机fractional-horse-power motor 小马力电动机fractional-horsepower asynchronous motor 分马力异步电动机fractional-horsepower motor 低功率电动机frame suspended motor 底架悬挂电动机; 底座悬挂型电动机frost-proof motor 耐寒式电动机full voltage starting motor 全电压起动电动机fully-flameproof motor 全防爆型电动机gas for motor fuel 气态发动机燃料; 动力煤气gas motor 煤气发动机; 煤气机gas-pressurized rocket motor 气压式液体火箭发动机gasoline motor 汽油发动机gasoline motor car 汽油车gate motor 栏木电动机gear head motor 齿轮减速电动机gear motor 齿轮电动机; 齿轮马达gear motor for screw conveyer 螺旋输送器减速电动机gear(ed) motor 减速电动机gear-type hydraulic motor 齿轮式液压马达gear-type motor 齿轮液压电动机gear-within-gear motor 内啮合齿轮马达geared motor 齿轮传动电动机; 齿轮传动马达; 齿轮电动机; 带变速齿轮箱的电动机; 带减速齿轮的电动机geared-down motor 齿轮减速发动机General Motor corporation (美国) 通用汽车公司general-purpose motor 通用电动机generator-motor set 发电机电动机组gimbal servo motor 万向伺服电动机gimbaled motor 悬挂式电动机gimbaling rocket motor 万向架支座火箭发动机glass reinforced plastic motor lifeboat 玻璃钢机动救生艇governor motor 调节马达; 调速电动机; 调速器电动机; 调速器用电动机; 调整机用电动机graduation of the motor currents 电动机电流级加法gramophone motor 唱机电动机grinding head motor 磨头电动机grinding head motor for woodworking 木工专用磨头电动机grinding wheel drive motor 砂轮电机gunmetals motor carriage 机械化炮车gyro motor 陀螺马达hand motor 手电动机harmonic motor 谐波电动机haulage motor 电机车head motor 头部发动机heat-pipe motor 热管冷却电动机heat-resistant motor 耐热电动机; 高温电动机heavy motor truck 重型载货汽车Hele-Shaw motor 径向活塞式液压电动机; 径向活塞式液压电动机hermetic motor 密封式电动机; 密封式电动机; 密封型电动机hermetically sealed motor 密封式电动机hermetically-sealed motor 密封型电动机heteropolar D.C. linear motor 多极直流直线电动机high capacity motor 高功率电动机high frequency motor generator 高频电动发电机high power motor 大功率电动机high slip motor 高转差率电机high speed low-noise synchronous motor 高速低噪音异步电动机high torque AC motor 大转矩交流电动机high torque and low speed motor 大转矩低速电动机high torque motor 高启动转矩电机high voltage motor 高压交流电动机high voltage wound asynchronous motor 高压卷线异步电动机high-capacity motor 大型电动机; 高功率电动机high-compression motor 高压缩发动机high-output three-phase induction motor 高功率三相感应电动机high-slip induction motor 高滑差感应电动机high-slip motor 高滑率电机high-speed motor 高速电动机high-speed servo motor 高速伺服电动机high-tension motor 高压电动机high-voltage motor 高压电动机high-voltage synchronous motor 高压同步电动机hoisting motor 升降电动机home motor 家用电动机homopolar motor 单极电动机horizontal induction motor 卧式感应电动机horizontal motor 卧式电动机horizontal-type motor 卧式发电机horse motor 马拉传动装置horse-drawn motorized duster 马拉机动喷粉机; 马拉式机动喷粉机hot mill motor 热轧电动机hot motor part detection 发动机发热部分探测hot motoring method 热机马达法hydraulic control motor 液压控制马达。
【精品】直流无刷电机外文资料原文及译文
直流无刷电机外文资料原文及译文外文资料原文Commutation Torque Ripple Reduction in BLDC Motor Using PWM_ON_PWM ModeGuangwei Meng, Hao Xiong, Huaishu Li Department of Electrical Engineering, Naval University of Engineering, Wuhan, China.Abstrac t--The paper analyzes the steady commutation process of the BLDC motor using PWM mode, confirms the commutation time to keep noncommutation phase current amplitude constant during commutation period by way of PWM in the period to implement the compensation control to eliminate commutation torque ripple under both low speed and high speed operation, investigates the effect by PWM mode on a three-phase six-state 120° turn-on BLDC motor, and presents torque ripple compensation control in PWM_ON_PWM mode, which can not only entirelyeliminate torque ripple resulted from the current emerging in the turn-off phase during non-commutation period but also compensate torque ripple caused by the commutation current during commutation period.Index Terms—BLDC motor, commutation, PWM, torque ripple.I. INTRODUCTIONThe BLDC motors have been widely used due to its features － a simple structure, good speed adjusting performance,high powerdensity, low noise and simple control, etc. It is a hotspot to suppress the torque ripple and improve the control performance of a BLDC motor with the trapezoidal back emf.BLDC motors usually operate in all kinds of PWM modes, which not only affect the dynamic loss of power switches and radiation uniformity, but also influence the torque ripple. It is an effective way to suppress the torque ripple through changing dc bus chopper control to remain non-commutation phase current amplitude constant, but it results into a more complex topology [1]-[3]. It is just fit for low speed applications to control non-commutation phase current amplitude to regulate the commutation torque ripple [4]. It is analyzed about the influence resulted from PWM ON mode on the torque ripple in [5].The ideas in [1]-[3] are to adopt different suppression methods in differ ent speed interval, but they don’t take the effect by PWM modes on the system in account. The predictive current, neural network control and activedisturbance rejection control etc are introduced to suppress the torque ripple in [9]-[12], but the control algorithm is more complicated and harder for realization.Depending on the commutation process of BLDC motors and the effect by PWM modes on the system, thepaper presents a torque ripple com-pensation control in PWM_ON_PWM mode at different speeds by seeking different PWM modulation ratios during commutation period as motor runs at low speed and high speed.Themethod retains the original to-pology, improves the control performance of the system dramatically,and moreover is easy to realize.II. ELECTROMAGNETIC TORQUE OF BLDC MOTORDURING COMMUTATION PROCESSAssume that the BLDC motor is three-phase symmetrical and Y- connected, and neglect eddy currents and hysteresis losses, its equivalent circuit and main circuit are shown in Figure 1. r, L are the resistance andinductance of the stator windings respectively;C B A e e e ,, are the counter emfs of the corresponding phase windings respectively; C B A i i i ,, are the corresponding phase currents respectively.0=++C B A i i i (1)The counter emf of every phase winding is a trapezoidal waveform with a flat-top width greater than or equal to 1200 electrical degree,and its flat-top amplitude is Em. When the motor works in three-phase six-state 1200 turn-on mode, the currents don’t commutates instantaneously as a result of the inductanceof the armature winding. Take the power switch 1T and 2T ’s turn -on to 2T and 3T ’s turn -on for example. During the commutation, it is gained as follows m C B A E e e e =-== (2)Suppose that the mechanical angular velocity of the rotor is Ω, the t oque can be obtained as follows during the commutation process.Ω=Ω++=C m C C B B A A e i E i e i e i e T 2 (3)It is obvious from (3) that the toque is proportional to the non-commutation phase current during commutation,i.e. the commutation torque ripple can be eliminated so long as non-commutation phase current remains constant during commutation. III. COMMUTATION PROCESS WITHOUT CONSIDERINGEFFECT BY PWM AND ARMATURE WINDING RESISTANTAssume that the circuit status changes from phase A and C’s turn -on to phase B and C’s turn -on, phase A current flows 4D and decays to zero gradually, while phaseB current increases to the maximum gradually and reaches its steady-state value.The circuit equation during commutation without considering the effect by PWM can be written as follows. ⎪⎩⎪⎨⎧=++-++=++-++d C C C B B B C C C A A A U e ri dt di L e ri dt di L e ri dt di L e ri dt di L )(0)( (4) Compared with the winding time constant rL of a BLDC motor, PWM period can be thought small enough,and then ()C B A X di di L ri tX X ,,=<<. So the effect of the armature winding resistant can be neglected. Moreover theinitial and final values of every phase current equal every phase steady-state current value 0I before and after the commutation. All phase currents during the commutation can be obtained from (1), (2) and(4). ()⎪⎪⎪⎩⎪⎪⎪⎨⎧--=-=+-=t L E U I i t L E U i t L E U I i m d C m d B m d A 34323200 (5) Then the toque during the commutation can be written ⎪⎭⎫ ⎝⎛-+Ω=t L E U I E T m dm e 3420 (6) From (5), the turn-off time off t ∼ of phase A and the turn-on time on t ∼ of phaseB during the commutation process are m d off E U LI t 230~+=(7) ()m d on E U LI t -=230~ (8)From (5)~(8), the commutation between two phases can’t be completed in the same time as m d E U 4> , i.e. the motor speed is less than a certain value, and as a result B i has reached its steady-state value before A i falls to 0, shown in Fig.2(I). What’s more, the commutation leads to an increase in the amplitude of torque. The torque ripple can be obtainedmd m d m r E U E U I E T --⋅Ω=40 (9) The commutation between two phases can be completed in the same time as m d E U 4= , i.e. The motor runs at a certain speed, and as a result B i has exactly reached its steady-state value just as A i falls to 0, shown in Fig.2(II). In this case, the torque remains constant during the commutation and its value equals the torque during the non-commutation processΩ=02I E T m e (10) As m d E U 4<, i.e. the motor speed is greater than a certain value, the commutation between two phases can’t be completed in the same time, and as a result B i doesn’t reached its steady-state value when A i falls to 0,shown in Fig.2(III). The commutation leads to a decrease in the amplitude of torque. The torque ripple can be obtained md m d m r E U E U I E T 2420+-⋅Ω= (11)IV. COMMUTATION TORQUE RIPPLE COMPENSATIONCONTROL IN PWM MODEIt is known based on the previous analysis that the torque ripple caused bycommutation can be finally eliminated by two ways-reducing current rate of increase in the turn-on phase to suppress the currentpulsation in the non-commutation phase as the motor speed is less than a certain value; commutation overlapping to keep theturn-on phase constantly on and use PWM mode in the power switches of the turnoffphases to decrease current rate of descend to suppress the current pulsation in the non-commutation phase as the motor speed is greater than a certain value.Assume that X S is the electric level state variables ()1,,,==X S C B A X represents turn-on of power switch or diode in the upper arm of the corresponding phase whie 0=X S represents turn-on of power switch or diode in the lower arm of thecorresponding phase.As the motor runs at a low speed, PWM is implemented on the turn-on phase, i.e. turn off phase A while PWM on phase B, in order to reduce current rate of increase in the turn-on phase during commutation. The circuit equation during commutation is ⎪⎪⎩⎪⎪⎨⎧=⎪⎭⎫ ⎝⎛++-++=⎪⎭⎫ ⎝⎛++-++d B C C C B B B C C C A A A U S e ri dt di L e ri dtdi L e ri dt di L e ri dt di L 0 (12) It can be obtained from (1), (2) and (12) ⎪⎩⎪⎨⎧==+=--=+0as 341as 34B m C C B m d C C S E ri dt di L S E U ri dt di L (13) So non-commutation phase current can be got ⎪⎪⎭⎫ ⎝⎛-⎪⎭⎫ ⎝⎛---=--t L r m d BB C e r E U D I I i 13400 (14) Where BB D is control pulse duty cycle of the turn-on phase during thecommutation.From (12) and (13), we can get ⎪⎩⎪⎨⎧=-=+=+-=+0as 321a 32B m A A B m d A A S E ri dt di L sS E U ri dt di L (15) So t L r m d BB m d BB A e r E U D I r E U D i -⎪⎭⎫ ⎝⎛++++=32320 (16)The turn-off time of the turn-off phase toff is ⎪⎪⎭⎫ ⎝⎛++=m d BB off E U D rI r L t 231ln 0 (17) From (14), the following equation must be satisfied in order to keep the amplitude of non-commutation phase current unvaried during commutation.dm BB U rI E D 034+= (18) Because 10≤≤BB D during commutation, it means that the inequation will besatisfied only if d m U rI E ≤+034, i.e. the motor runs at a low speed. Furthermore as the machine operates at a low speed, it can be obtained from (14) (1) When dm BB U rI E D 034+<, i.e. Undercompensated control during commutation, the amplitude of non-commutation phase current decreases during commutation. (2) When d m BB U rI E D 034+>, i.e. Overcompensated control during commutation, the amplitude of noncommutation phase current increasesduring commutation.Substitute (18) into (17), we can get the commutation time that keeps the amplitude of non-commutation phase current constant during commutation as the machine operates at a low speed. ⎪⎪⎭⎫ ⎝⎛++=m c E rI rI r L t 21ln 00 (19) As the motor runs at a high speed, overlapping commutation is adopted to implement PWM on the turn-off phase and turn on the turn-off phase constantly,i.e. PWM on phase A while turn on phase B constantly,in order to reduce non-commutation current ripple during commutation. The circuit equation during commutation is ⎪⎪⎩⎪⎪⎨⎧=⎪⎭⎫ ⎝⎛++-++=⎪⎭⎫ ⎝⎛++-++d C C C B B B d A C C C A A A U e ri dt di L e ri dt di L U S e ri dt di L e ri dt di L (20) It can be obtained from (1), (2) and (20) ⎪⎩⎪⎨⎧=-=+=-=+0as 341as 342A A S E U ri dtdi L S E U ri dt di L m d C C m d C C (21) So non-commutation phase current can be got ⎪⎪⎭⎫ ⎝⎛-⎪⎭⎫ ⎝⎛-+--=--t L r m d AA dC e r E UD U I I i 13400 (22) Where DAA is control pulse duty cycle of the turn-off phase during the commutation. From (20) and (21), we can get⎪⎩⎪⎨⎧=-=+=-=+0as 3221as 32A A S E U ri dtdi L S E U ri dt di L m d B B m d B B (23) Therefore turn-on phase current can be worked out.()()t L r d AA m d d AA m d B e rU D E U r U D E U i ------=3232 (24) The turn-on time of the turn-on phase t on is ()()⎥⎦⎤⎢⎣⎡-----=0322ln rI U D E U U D E U r L t d AA m d d AA m d on (25) From (22), the following equation must be satisfied in order to keep the amplitude of non-commutation phase current unvaried during commutation. 1340-+=dm AA U rI E D (26) Because 10≤≤AA D during commutation, it means that the inequation will be satisfied only if d m U rI E ≥+034,i.e. the motor runs at a high speed. Furthermore as the machine operates at a high speed, it can be obtained from (22)(1) When 1340-+<dm BB U rI E D i.e. Undercompensated control during commutation, the amplitude of non-commutation phase current decreasesduring commutation. (2) When 1340-+>d m BB U rI E D , i.e. Overcompensated control during commutation, the amplitude of non-commutation phase current increases during commutation.Substitute (26) into (25), we can get the commutation time that keeps the amplitude of noncommutation phase current constant during commutation(2) as the machine operates at a high speed. ⎪⎪⎭⎫ ⎝⎛----=0021ln rI E U rI r L t m d c (27)The same conclusion can be drawn when a similar analysis is carried out for the lower armsV. TORQUE RIPPLE REDUCTION IN PWM MODEIn [14] and [15], a new PWM mode is presented －PWM _ON _PWM, i.e. using PWM mode in the first30°and the last 30° while keeping constant turn-onmode in the middle 60°. The mode can entirely eliminate the emerging current in the turn-off phase during non-commutation and thus reduce the torqueripple during non-commutation.PWM _ON _PWM is a bilateral modulation, but the dynamic losses of power switches in the mode are equal to those of unilateral modulation. Six switches aremodulated in turn, so the power switches have a uniform radiation and the system has a higher reliability. The mode is employing PWM on the turn-on power switchesand thus it can suppress the torque ripple during commutation to a certain extent even if a compensation control is not applied at a low speed.In PWM _ON _PWM mode, it can not only eliminate the torque ripple during non-commutation but also suppress the commutation torque ripple at low speed operation by keeping d m BB U rI E D 034+=in the commutation compensation control time ⎪⎪⎭⎫ ⎝⎛++=m c E rI rI r L t 21ln 00 at low speed operation, i.e.d m U rI E ≤+034.At high speed operation i.e.d m U rI E ≥+034,overlapping commutation is used to keep the turn-on phase constantly on and make the control pulse duty cycle of the turn-off phase 1340-+=dm AA U rI E D in the commutation compensation control time ⎪⎪⎭⎫ ⎝⎛----=0021ln rI E U rI r L t m d c ,which can not only eliminate the torque ripple during noncommutation but also suppress the commutation torque ripple at high speed operation. A simulation is carried out to verify the method.The parameters areN T m r n V U m kg J r mH L L N N 4.0,1600,48,0157.0,66.0,262===⋅=Ω==.In non-full-bridge modulation mode such as H_PWM-L_ON mode, power switches in the upper arms use PWM mode while the others in the lowerarms use constant turn-on mode in 1200 turn-on interval. The simulation waveform of phase current is shown in Fig. 3. It is obvious that a current emerges in the turn-off phase during non-turn-on period and its pulsating frequency is the same as the modulatingfrequency while its amplitude varies with the variation of back emf amplitude, which produces a reverse torque.The simulation waveform of phase current in PWM _ON _PWM mode is shown in Fig.4. It is obvious that no current emerges in the turn-off phase during non-turnon period, which reduces the torque ripple during noncommutation compared with other PWM mode.Fig.5 shows the waveforms of the phase current and torque at low speed with PWM pulse duty cycle DA=0.2 without compensation control. Fig. 6 shows thewaveforms of the phase current and torque at low speed with the control pulse duty cycle DBB=0.4 in the turn-on phase within the commutation time tc=0.0013 by a compensation control. The comparison indicates that the torque ripple caused by commutation can be almost eliminated by means of a commutation compensation control at low speed application.It is found from Fig.3 to Fig.8 that using a commutation compensation control in PWM_ON_PWM mode can not only avoid the torque ripple caused by the emerging current in the turn-off phase during noncommutation but also effectively suppress the commutation torque ripple at both low speed and high speed applications.VI. CONCLUSIONSBased on the analysis of commutation process of BLDC motor and the effect by PWM mode on the control system, a commutation compensation control inPWM_ON_PWM mode is worked out, which can not only eliminate torque ripple resulted from the current emerging in the turn-off phase during non-commutation period but also compensate commutation torque ripple. A control system without torque ripple can be realized through the method under both low speed and high speed operation.REFERENCES[1] S. Wang, T. Li, and Z. Wang, “Commutation torque ripple reduction in brushless DC motor drives using a single current sensor,” Electric Machines and Control, vol. 12,pp. 288-293, March. 2008.[2] X. Zhang and Z. Lü, “New BLDCM drive method to smooth the torque,” Power Electronics, vol. 41, pp. 102-104, Feb. 2007.[3] H.J. Song and C. Ick. “Commutation torque ripple reduction in brushless DC motor drivers using a single DC current sensor，” IEEE Trans. On Power Electr, vol. 19,pp. 312-319, Feb. 2004.[4] G.H. Kim, J. Seog and S.W. Jong, “Analysis of the commutation torque ripple effect for BLDCM fed by HCRPWM-VSI,” Proc. of APEC’92, 1992, pp.277-284. [5] X. Zhang and B. Chen, “The different influences of four PWM modes on commutation torque ripples in brushless DC motor control system,” Electric Machines and Control,vol.7, pp. 87-91, Feb. 2003.[6] D. Chen, Z. Liu and J. Ren et al, « Analysis of effects onBLDCM torque ripple by PWM modes,”. Electrical Drivers, vol.35, pp. 18-20, April 2005.[7] G. Jie and W. Ma, “Research on the Plus-Width Modulation methods of Brushless DC motor taking consideration of commutation,” Transactions of China Electrotechnical Society, vol.20, pp. 66-71, Sep. 2005.[8] X. Bao and Y. Zhang, “Analysis of commutation torque ripple of brushless DC motor and its minimization methods,” Small & Speciall Electrical Machines, vol.30, pp. 14-17, Feb. 2007.[9] P. Lin, K. Wei and Z. Zhang, “A novel control scheme to suppress the commutation torque ripple in BLDCM,” Proc.of the CSEE, vol.26, pp. 153-158, March 2005.[10] J. Cao, B. Cao, and P. Xu, et al, “Research on torque ripple minimization of position-sensorless brushless DC motor,”Electric Machines and Control, v ol.12, pp. 248-253,March 2008.[11] C. Xia, D. Wen, and J. Wang, “A new approach of minimizing commutation torque ripple for brushless DC motor based on adaptive ANN,” Proc. of the CSEE, vol.22,pp. 54-58, April 2002.[12] C. Xia, W. Yu, and Z. Li, “Torque ripple reduction of PM brushless DC motors based on auto-disturbances-rejection controller,” Proc. of the CSEE, vol.26, pp. 137-142, Dec.2006.[13] F. Yuan, S. Huang and R. Li, “Study on PWM modulation mode of permanent magnet brushless DC moto,”Micromotor s, vol.37, pp. 42-44, May. 2004.[14] K. Wei, C. Hu, and Z. Zhang. “A novel PWM scheme to eliminate the diode freewheeling of the incative phase in BLDC moto,” Proc. of the CSEE, vol.25, pp. 104-108, July 2005.[15] K. Wei, P. Lin and Y. Xiong et al, “Rese arch on PWM metod in brushless DC motor,” Journal of Zhejiang University (Engineering Science), vol.39, pp. 1038-1042, July 2005.外文资料译文用PWM_ON_PWM模式抑制无刷直流电机换相引起的脉动转矩中国武汉海军工程大学电机工程学系蒙广伟、雄郝、李怀树编摘要—本文分析了无刷直流电动机采用PWM控制稳定换相的过程，证实了运用PWM模式，在换相时控制非换相相电流幅度稳定不变，并进行补偿以消除低速和高速运转下的换相转矩脉动；研究了运用三相六阶的PWM模式起动无刷直流电机的方法，并提出基于脉宽调制的PWM模式如何抑制转矩脉动，PWM控制不仅可以消除非换相期间由关断电流引起的转矩脉动，还可以补偿换相期间由换相电流引起的转矩脉动。
直流电机中英文对照外文翻译文献
中英文资料对照外文翻译原文：Introduction to D.C. MachinesD.C. machines are characterized by their versatility. By means of various combinations of shunt-, series-, and separately excited field windings they can be designed to display a wide variety of volt-ampere or speed-torque characteristics for both dynamic and steady state operation. Because of the ease with which they can be controlled, systems of D.C. machines are often used in applications requiring a wide range of motor speeds or precise control of motor output.The essential features of a D.C. machine are shown schematically. The stator has salient poles and is excited by one or more field coils. The air-gap flux distribution created by the field winding is symmetrical about the centerline of the field poles. This is called the field axis or direct axis.As we know, the A.C. voltage generated in each rotating armature coil is converted to D.C. in the external armature terminals by means of a rotating commutator and stationary brushes to which the armature leads are connected. The commutator-brush combination forms a mechanical rectifier, resulting in a D.C. armature voltage as well as an armature m.m.f. Wave then is 90 electrical degrees from the axis of the field poles, i.e. in the quadrature axis. In the schematic representation the brushes are shown in quadrature axis because this is the position of the coils to which they are connected. The armature m.m.f. Wave then is along the brush axis as shown. (The geometrical position of the brushes in an actual machine is approximately 90 electrical degrees from their position in the schematicdiagram because of the shape of the end connections to the commutator.)The magnetic torque and the speed voltage appearing at the brushes are independent of the spatial waveform of the flux distribution; for convenience we shall continue to assume a sinusoidal flux-density wave in the air gap. The torque can then be found from the magnetic field viewpoint.The torque can be expressed in terms of the interaction of the direct-axis air-gap flux per pole d φ and space-fundamental component 1Fa of the armature m.m.f.wave. With the brushes in the quadrature axis the angle between these fields is 90 electrical degrees, and its sine equals unity. For a P pole machine2122d P T Fa πφ⎛⎫= ⎪⎝⎭（1-1） In which the minus sign gas been dropped because the positive direction of the torque can be determined from physical reasoning. The space fundamental 1Fa of the sawtooth armature m.m.f.wave is 28π times its peak. Substitution in above equation then gives()2a a a PC T i N m mφπ=∙ （1-2） Where, a I =current in external armature circuit;a C =total number of conductors in armature winding;m =number of parallel paths through winding. And2a a PC K m π= （1-3） is a constant fixed by the design of the winding.The rectified voltage generated in the armature has already been discussed before for an elementary single-coil armature. The effect of distributing the winding in several slots is shown in figure. In which each of the rectified sine wave is the voltage generated in one of the coils, commutation taking place at the moment when the coil sides are in the neutralzone. The generated voltage as observed from the brushes and is the sum of the rectified voltages of all the coils in series between brushes and is shown by the rippling line labeled a e in figure. With a dozen or so commutator segments per pole, the ripple becomes verysmall and the average generated voltage observed from the brushes equals the sum of the average values of the rectified coil voltages. The rectified voltage a e between brushes, Known also as the speed voltage, is2a a d m a d m PC e K mφωφωπ== （1-4） where a K is the design constant. The rectified voltage of a distributed winding has thesame average value as that of a concentrated coil. The difference is that the ripple is greatly reduced.From the above equations, with all variable expressed in SI units,a a m e i T ω= （1-5）This equation simply says that the instantaneous power associated with the speed voltage equals the instantaneous mechanical power with the magnetic torque. The direction of power flow being determined by whether the machine is acting as a motor or generator. The direct-axis air-gap flux is produced by the combined m.m.f.f f N i ∑ of the fieldwindings. The flux-m.m.f. Characteristic being the magnetization curve for the particular iron geometry of the machine. In the magnetization curve, it is assumed that the armature –m.m.f. Wave is perpendicular to the field axis. It will be necessary to reexamine this assumption later in this chapter, where the effects of saturation are investigated more thoroughly. Because the armature e.m.f. is proportional to flux times speed, it is usually more convenient to express the magnetization curve in terms of the armature e.m.f. 0a e at a constant speed 0m ω. The voltage a e for a given flux at any other speed m ω is proportional to the speed, i.e.00m a a m e e ωω= （1-6）There is the magnetization curve with only one field winding excited. This curve can easily be obtained by test methods, no knowledge of any design details being required.Over a fairly wide range of excitation the reluctance of the iron is negligible compared with that of the air gap. In this region the flux is linearly proportional to the total m.m.f. of the field windings, the constant of proportionality being the direct-axis air-gap permeance.The outstanding advantages of D.C. machines arise from the wide variety of operating characteristics that can be obtained by selection of the method of excitation of the field windings. The field windings may be separately excited from an external D.C. source, or they may be self-excited; i.e. the machine may supply its own excitation. The method of excitation profoundly influences not only the steady-state characteristics, but also the dynamic behavior of the machine in control systems.The connection diagram of a separately excited generator is given. The required field current is a very small fraction of the rated armature current. A small amount of power in the field circuit may control a relatively large amount of power in the armature circuit; i.e. the generator is a power amplifier. Separately excited generators are often used in feedback control systems when control of the armature voltage over a wide range is required. The field windings of self-excited generators may be supplied in three different ways. The field may be connected in series with the armature, resulting in a series generator. The field may be connected in shunt with the armature, resulting in a shunt generator, or the field may be in two sections, one of which is connected in series and the other in shunt with the armature, resulting in a compound generator. With self-excited generators residual magnetism must be present in the machine iron to get the self-excitation process started.In the typical steady-state volt-ampere characteristics, constant-speed prime movers being assumed. The relation between the steady state generated e.m.f. a E and the terminal voltage t V ist a a a V E I R =- （1-7）where a I is the armature current output and a R is the armature circuit resistance. In agenerator,a E is larger than t V and the electromagnetic torque T is a counter torque opposing rotation.The terminal voltage of a separately excited generator decreases slightly with increase in the load current, principally because of the voltage drop in the armature resistance. The field current of a series generator is the same as the load current, so that the air-gap flux and hence the voltage vary widely with load. As a consequence, series generators are normally connected so that the m.m.f. of the series winding aids that of the shunt winding. The advantage is that through the action of the series winding the flux per pole can increase with load, resulting in a voltage output that is nearly usually contains many turns of relatively small wire. The series winding, wound on the outside, consists of a few turns of comparatively heavy conductor because it must carry the full armature current of the machine. The voltage of both shunt and compound generators can be controlled over reasonable limits by means of rheostats in the shunt field.Any of the methods of excitation used for generators can also be used for motors. In the typical steady-state speed-torque characteristics, it is assumed that motor terminals are supplied from a constant-voltage source. In a motor the relation between the e.m.f. a E generated in the armature and terminal voltage t V ist a a a V E I R =+ （1-8） where a I is now the armature current input. The generated e.m.f. a E is now smaller than the terminal voltage t V , the armature current is in the opposite direction to that in a generator, and the electron magnetic torque is in the direction to sustain rotation of the armature.In shunt and separately excited motors the field flux is nearly constant. Consequently increased torque must be accompanied by a very nearly proportional increase in armature current and hence by a small decrease in counter e.m.f. to allow this increased current through the small armature resistance. Since counter e.m.f. is determined by flux and speed, the speed must drop slightly. Like the squirrel-cage induction motor, the shunt motor issubstantially a constant-speed motor having about 5% drop in speed from no load to full load. Starting torque and maximum torque are limited by the armature current that can be commutated successfully.An outstanding advantage of the shunt motor is case of speed control. With a rheostat in the shunt-field circuit, the field current and flux per pole can be varied at will, and variation of flux causes the inverse variation of speed to maintain counter e.m.f. approximately equal to the impressed terminal voltage. A maximum speed range of about 4 or 5 to I can be obtained by this method. The limitation again being commutating conditions. By variation of the impressed armature voltage, very speed ranges can be obtained.In the series motor, increase in load is accompanied by increase in the armature current and m.m.f. and the stator field flux (provided the iron is not completely saturated). Because flux increase with load, speed must drop in order to maintain the balance between impressed voltage and counter e.m.f. Moreover, the increased in armature current caused by increased torque is varying-speed motor with a markedly drooping speed-load characteristic. For applications requiring heavy torque overloads, this characteristic is particularly advantageous because the corresponding power overloads are held to more reasonable values by the associated speed drops. Very favorable starting characteristics also result from the increase flux with increased armature current.In the compound motor the series field may be connected either cumulatively, so that its m.m.f. adds to that of the shunt field, or differentially, so that it opposes. The differential connection is very rarely used. A cumulatively compounded motor has speed-load characteristic intermediate between those of a shunt and a series motor, the drop of speed with load depending on the relative number of ampere-turns in the shunt and series fields. It does not have disadvantage of very high light-load speed associated with a series motor, but it retains to a considerable degree the advantages of series excitation.The application advantages of D.C. machines lie in the variety of performance characteristics offered by the possibilities of shunt, series and compound excitation. Some of these characteristics have been touched upon briefly in this article. Still greaterpossibilities exist if additional sets of brushes are added so that other voltages can be obtained from the commutator. Thus the versatility of D.C. machine system and their adaptability to control, both manual and automatic, are their outstanding features.A D.C machines is made up of two basic components:－The stator which is the stationary part of the machine. It consists of the following elements: a yoke inside a frame; excitation poles and winding; commutating poles (composes) and winding; end shield with ball or sliding bearings; brushes and brush holders; the terminal box.－The rotor which is the moving part of the machine. It is made up of a core mounted on the machine shaft. This core has uniformly spaced slots into which the armature winding is fitted. A commutator, and often a fan, is also located on the machine shaft.The frame is fixed to the floor by means of a bedplate and bolts. On low power machines the frame and yoke are one and the same components, through which the magnetic flux produced by the excitation poles closes. The frame and yoke are built of cast iron or cast steel or sometimes from welded steel plates.In low-power and controlled rectifier-supplied machines the yoke is built up of thin (0.5～1mm) laminated iron sheets. The yoke is usually mounted inside a non-ferromagnetic frame (usually made of aluminum alloys, to keep down the weight). To either side of the frame there are bolted two end shields, which contain the ball or sliding bearings.The (main)excitation poles are built from 0.5～1mm iron sheets held together by riveted bolts. The poles are fixed into the frame by means of bolts. They support the windings carrying the excitation current.On the rotor side, at the end of the pole core is the so-called pole-shoe that is meant to facilitate a given distribution of the magnetic flux through the air gap. The winding is placed inside an insulated frame mounted on the core, and secured by the pole-shoe.The excitation windings are made of insulated round or rectangular conductors, and are connected either in series or in parallel. The windings are liked in such a way that the magnetic flux of one pole crossing the air gap is directed from the pole-shoe towards thearmature (North Pole), which the flux of the next pole is directed from the armature to the pole-shoe (South Pole).The commutating poles, like the main poles, consist of a core ending in the pole-shoe and a winding wound round the core. They are located on the symmetry (neutral) axis between two main poles, and bolted on the yoke. Commutating poles are built either of cast-iron or iron sheets.The windings of the commutating poles are also made from insulated round or rectangular conductors. They are connected either in series or in parallel and carry the machine's main current.The rotor core is built of 0.5～1mm silicon-alloy sheets. The sheets are insulated from one another by a thin film of varnish or by an oxide coating. Both some 0.03～0.05mm thick. The purpose is to ensure a reduction of the eddy currents that arise in the core when it rotates inside the magnetic field. These currents cause energy losses that turn into heat. In solid cores, these losses could become very high, reducing machine efficiency and producing intense heating.The rotor core consists of a few packets of metal sheet. Redial or axial cooling ducts (8～10mm inside) are inserted between the packets to give better cooling. Pressure is exerted to both side of the core by pressing devices foxed on to the shaft. The length of the rotor usually exceeds that of the poles by 2～5mm on either side－the effect being to minimize the variations in magnetic permeability caused by axial armature displacement. The periphery of the rotor is provided with teeth and slots into which the armature winding is inserted.The rotor winding consists either of coils wound directly in the rotor slots by means of specially designed machines or coils already formed. The winding is carefully insulated, and it secured within the slots by means of wedges made of wood or other insulating material.The winding overcharge are bent over and tied to one another with steel wire in order to resist the deformation that could be caused by the centrifugal force.The coil-junctions of the rotor winding are connected to the commutator mounted onthe armature shaft. The commutator is cylinder made of small copper. Segments insulated from one another, and also from the clamping elements by a layer of minacity. The ends of the rotor coil are soldered to each segment.On low-power machines, the commutator segments form a single unit, insulated from one another by means of a synthetic resin such as Bakelite.To link the armature winding to fixed machine terminals, a set of carbon brushes slide on the commutator surface by means of brush holders. The brushes contact the commutator segments with a constant pressure ensured by a spring and lever. Clamps mounted on the end shields support the brush holders.The brushes are connected electrically－with the odd-numbered brushes connected to one terminal of the machine and the even-numbered brushes to the other. The brushes are equally spaced round the periphery of the commutator－the number of rows of brushes being equal to the number of excitation poles.译文：直流电机的介绍直流电机的特点是他们的多功用性。
发电机和电气设备毕业论文外文文献翻译.doc
Generator and Electrical EquipmentsGeneratorIntroductionElectric generators convert mechanical energy to electrical energy，which is more easily transmitted to remotely located points of application. The first large electric generating systems used direct-current (dc) generators，mainly because direct current was better understood than alternating current (ac). However，dc generators are limited to generating power at relatively low voltages，largely due to problems at their commutates.As power networks developed，higher and higher voltages were required to transmit large blocks of power over longer and longer distances. Electric transformers can easily change the normally low voltage generated to the high voltages needed for efficient power transmission, and of course, transformers only work on alternating current. Ac generators, or alternators as they are commonly called，are so much simpler mechanically, so much more efficient, and require so much less maintenance than dc machines that all large generating plants output alternating current today. Although de transmission lines can transport extremely large blocks of power very efficiently over long distances, the power is always generated as alternating current, transformed to the voltage required，rectified and transmitted as direct current, and then inverted back to alternating current at the point of application.Mechanical EnergyThe mechanical energy for driving the generator must be derived from a source with enough reliability and capacity to make it economically feasible to develop and transmit the energy electrically to the point of use. A small water supply running only during exceptionally wet years or located at a great distance from electrical consumers would probably not be suitable. Mechanical energy sources which cannot be moved, such as hydraulic turbines or even wind machines, must have the cost of transporting the energy produced (among other factors) taken into account when overall costs are calculated. Steam-turbine power plants，however，can be located near a coal seam，lumber mill，or a reliable source of cooling water to save on transportation costs. Some mechanical power may be obtained from sources more easily located near the point of utilization. Gas turbines and reciprocating gas or diesel engines fall into this category. Except for standby emergency power generators，even here it might be more economical to install large units and transmit the power to the point of use. Large power plants will generally have better operating efficiencies than small ones，and it may be desirable to locate a large plant near the center of use and then distribute the power generated outward，assuming the fuel supply is transportable.Each type of mechanical driver has its own peculiarities, and some have a sizable impact on the generator configuration. There are marked differences as to the engine output Speeds available, the speed pulsations possible, the chances of overspeed，etc..Normally，the generator shaft is horizontal and direct-connected to the driver. Sometimes speed-changing gear boxes are installed between a high-speed turbine and a lower - speed generator. These allow the turbine to run at its most efficient speed，a speed that may be too high for the generator. Small hydraulic turbines usually have their shafts mounted horizontally; large hydraulic machines have their shafts direct-connected and vertically mounted. The generator may include special bearings to carry the thrust imposed by the water flowing through the turbine. Criteria like these for providing mechanical energy impose special designs on the generating machines.Basic Principle and ConstructionThere are two quite distinct forms of modem alternator. While the principle of operation of each is the same，i.e.，the movement of magnetic poles past stationary coils，their constructions are very different. The reason for this is that each has been designed to ’match’ its prime mover, i.e., to suit the mechanical device that is to tap the two principal natural power resources-failing water，on the one hand，and steam, generated by heat from fossil fuels or nuclear fuels，on the other.To match the output of the turbo alternators，the water wheel generators must therefore be multi-polar and hence of large diameter and small axialength. There is a limit to the length of a turbo alternator, based largely on the mechanical considerations involved in supporting a large rotor mass between a bearing at each end. At 3 000 or 3 600 r/min (50 or 60 Hz) the rotor must be extremely well balanced and its surface smooth. With the lower speed water powered machine，such precautions can be relaxed with a view to making the larger rotor cheaper to make.The fundamental difference in shape between the rotors of the two types of machine is consequent upon the above considerations，but now a secondary difference is introduced by what could be termed the experience and skill of the designer.It is necessary to produce a sine wave of induced The factors that affect the instantaneous value e of this are the flux density b，the length I of the conductor，and the velocity v (the use of small letters indicating the instantanous values). Thus:e = bl v (4.1)A reasonably clear definition of what constitutes a 1pole1can be given by defining a pole pitch rather than a pole per se. A pole pitch is the distance ( p ) between points where the current flow is a maximum. The number of poles in the machine is then the periphery ( 2 n r ) divided by p . This definition fits easily into linear motor technology, where the number of poles need be neither even nor an integer. The speed of rotation expressed in Table 4.1 as 2 f/n r/s，where n was the number of poles, can always be converted to a linear speed, for the periphery 2〜r contains n pole pitcheseach of length p so that 2 丌r = n p • Hence the rotational speed 2 f/n /r/s ’translates f into a linear speed，v s，such thatv s=(2 f / n) (2 H r)= (2 f / n) (n p)=2pf (4.2) which is simply the ’common sense' statement that a travelling wave moves twopole pitches ( = one wavelength; A ) each cycle of events. (This corresponds to the well known formula v = f 入for all wave motions.)Three-phase machine stator shown in Figure 4. 1 (a). It does not，as it appears at first sight, have six poles，even th ough it has six obvious ’polar projections’. These are to be seen as six 1teeth’ in a slotted stator with a three-phase ’distributed’ winding, except that the distribution has virtually disappeared except insofar as there are three phases. Unless such a diagram makes clear how the two coils in each phase are connected，no one can say whether it has two poles or four. It is worth studying Figure 4.1 carefully, first to appreciate the differences between(b)and (c)，hence to r see’ the kind of difficulty that can arise in the mind of the student being confronted with the problem for the first time，and finally to demolish the problem so that it never arises in the future. For the connections shown at (b)，both red-phase coils assist each other in driving flux diametrically across the machine. So do both yellow-phase coils and both blue-phase coils. So, whatever instantaneous currents flow in the system as a whole，the resultant flux will be the vector sum of three diametral fluxes which therefore is itself diametral and the machine corresponds to the two-pole system. But if opposite pairs send opposing fluxes into the rotor then the only possible resultant flux pattern corresponds to that of Figure 4.1 (c) and the machine has four poles.Figure 4.! How pole number depends on connections betweeen coils <rf (be same phase (CMythe red phase is shown for clarity)In this crude example the lack of winding •distribution’ is now obvious，since a two-pole, three-phase machine with only six slots has one slot per pole per phase, or, as is now more ’fashionably’ written, one slot per pole and phase，The four-pole version has only half a slot per pole and phase，which gives a very ’ lumpy1 kind of travelling field to be avoided in practice if at all possible by having a larger number of slots. The reader w-ill appreciate，however，that if a more realistic example of two-and four-pole machines with，say，twenty-four slots each had been chosen, the diagrams might have become too obscure to make the point about ’pole counting1.(1 ) StatorsThe rapidly varying magnetic flux in the stator iron causes hysteresis losses as the iron resists changes in the flux density. The varying magnetic flux also causes electric currents, called eddy currents, to flow in the iron laminations; losses also result from this current flow. The stator is built from thin laminations to minimize the electrical losses and of specially rolled silicon steel to minimize the hysteresis losses. For small machines，the laminations are circular，in the shape of the finished stator. For large machines，the laminations are punched as semicircles and then assembled into the finished circular stator. Slots are punched for future installation of the windings.The winding slots are suitably insulated to provide both electrical insulation between the windings and the grounded stator and protection from abrasion damage to the windings by the stator iron. Windings are specified with the proper span, wire size, and amount of insulation required by the machine rating.For smaller machines, the windings are wound with loose coils of round wire’，which are inserted into the slots provided in the stator，mm by mm，and fastened with slot wedges to prevent movement of the windings. To get as much conductor and stator iron as possible into the machine, large units are wound with square or rectangular wire，which is formed into rigid coils with insulation both between the individual wires and around the coils themselves. The coils are inserted into the stator slots，which have parallel walls to provide a snug fit between the coils and the stator iron; slot wedges hold the coils in place. Coil ends are connected into the proper groupings to provide the configuration of poles，voltage, and other parameters for which the machine is rated.(2)RotorsTwo basic types of rotors see service in synchronous alternators. High-speed machines (two-and four-pole) are built with round rotors; slots are cut into the rotor for the field windings. These alternators are referred to as uniform-air-gap machines.Slower-speed machines have field poles that stick out from the rotor shaft, with the field winding wound around the projecting poles. The air gap obviously is not uniform. These alternators are called salient-pole machines.Each pole on the alternator rotor has a winding through which direct current，usually at 63 125 250，or 375 V，is circulated to ’’excite” the field and create a magnetic field. The power required for field excitation is normally only a small percentage of the output，about 1 to 2 percent of the alternator rating. The dc excitation is obtained either from direct-connected machines driven by a prime mover or from separately mountedexciters that &five their power from other sources. The exciter output voltage level must be adjustable and have enough capacity to enable the alternator to produce rated voltage at rated output.(3)ExcitersOver the years，field excitation has been provided by three main exciter designs rotating brush, rotating brush less，and static types.Rotating Brush Type. Rotating，compound-wound de designs were the only exciters used for many years. Exciters driven via a speed-increasing belt-and-pulley arrangement were sometimes specified so that less expensive, higher-speed exciters could be paired with slower-speed alternators. Direct current is delivered to the alternator rotor slip rings, which consist of two circular brass-alloy rings mounted on and insulated from the alternators shaft. Connections are made from the slip rings to the alternator field. Brushes riding on the slip rings are connected to the exciter.The rotating brush exciter still sees service，but continual maintenance problems are These problems，together with the development of reliable，inexpensive semiconductors, make the brush less exciter the dominant choice today.Brush less Type. The brush less exciter is simply a special type of alternator mounted on the same shaft as the main exciter. It is special because its field, which must be excited with direct current，is stationary，and its ac output comes from the rotating parts. The output is rectified and connected to the main alternator, s field by means of cables run along and fastened to the alternator shaft. Brushes, commutators, slip rings，and their maintenance are eliminated.Static Type. As prices go down and the reliability and ratings of semiconductors go up, special cubicle-mounted controlled rectifiers，called static exciters，are becoming an increasingly popular choice. Their lower cost, reduced losses，reduced maintenance, and more flexible outputs also make them good choices for replacements of damaged rotating exciters.A static exciter consists of an input transformer, silicon controlled rectifiers (SCRs), rectifier controls，and voltage regulator controls. The complete assembly functions to rectify the incoming ac voltage into a properly controlled dc exciter voltage required by the alternator. Static exciter input may be connected to any convenient ac powersource，such as station power (assuming it is available when the alternator is not running), but it is normally connected to the alternator output leads. Fuses and disconnect switches are installed between the alternator and exciter to protect against faults in the system.Once an alternator field winding has had direct current passed through it，a small amount of residual magnetism remains. When the alternator is run again at rated speed，without excitation，an ac voltage of 2 to 10 percent of rated can be measured at the alternator1 s output terminals. This voltage is generated by the residual magnetic flux in the rotor a cting on the stator windings. When it is connected to the alternator’s output，the static exciter rectifies this residual ac voltage into direct current, which is applied to the alternator field windings. This action further increases the excitation,which builds up until，in a very short time，the rated output voltage is obtained. Obviously，the correct connections must be made; if the output of the static exciter is in opposition to that of the residual voltage，no buildup will occur.The exciter output is connected to the alternator field via the slip rings, which will require some brush and ring maintenance, but not as much as is required by the brash and commutator arrangement in a rotating exciter. Sometimes the residual magnetism is lost or it is desirable to reverse the direction of the residual magnetism. The field can be "flashed” by momentarily connecting a battery，to the alternator field to establish some residual magnetism in the correct direction.On some static exciters this field flashing is done automatically every time the unit is started.Static exciters also find application where the alternator must have special response characteristics，such as for starting abnormally large motors. The starting current of an induction motor is on the order of 6 times its normal full-load current. Starting a large motor(larger than one-haft the generator load) causes the generator output voltage to drop，possibly enough to cause the motor starters to drop out. Reduced-voltage starters of several types are available to reduce the motor-starting current，but they are expensive and introduce time delays that may not be desirable. A static exciter can be provided with special" field forcing" equipment to give a quick increase in excitation in response to the demands of starting a large induction motor. Field forcing allows the generator to be smaller and less expensive than if standard equipment were used.(4)Motor-generator setsMotor-Generator Sets Separately mounted de generators driven by engines or ac motors are sometimes used as exciters. They are called motor-generator sets. The sets are occasionally specified as a replacement for a damaged direct-connected exciter. At one time，special types of motor-generator sets with voltage-regulating exciters were also used.发电机和电气设备发电机概述发电机是将机械能转化成电能的电力设备，而电能可以很容易地传输给远距离的用户。
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The three-phase induction motor speed control methodThree-phase asynchronous motor speed formula: N = 60f / p (1-s) Can be seen from the above formula, change the power supply frequency f, motor pole number p and the slip s may be too much to change the speed of purpose. From the speed of the essence of view, is simply a different way to change speed synchronous AC motor does not change the sync transfer speed or two.Widespread use in production machines without changing the synchronous speed of motor speed control method Wound Rotor Series Resistance Speed, chopper speed control, cascade control, and application of electromagnetic slip clutch, fluid couplings, clutches and other film speed. Change the synchronous speed of change on the number of stator pole multi-speed motor to change the stator voltage and frequency to frequency conversion with no change to the motor speed and so on.Energy from the speed point of view when, with high speed method and inefficient methods of two kinds of speed: high speed when the slip refers to the same, so no slip losses, such as multi-speed motors, Slip frequency control and loss can speed recovery methods (such as cascade control, etc.). A deteriorating loss of speed control methods are inefficient speed, such as series resistance of the rotor speed method, the energy loss in the rotor circuit on; Electromagnetic Clutch The speed method, the energy loss in the clutch coils; fluid coupling speed, energy loss in the fluid coupling of the oil. General deterioration in loss increased with the expansion speed range, if not speed range, the energy loss is minimal.1, variable speed control method of pole pairsThis speed is then used to change the stator winding way to change the red cage motor stator pole pairs to achieve speed control purposes, the followingfeaturesWith hard mechanical properties, good stability;No slip loss, high efficiency; Wiring simple, easy to control, low price;A level speed, differential large, can not get smooth speed control;With pressure and speed adjustment, with the use of electromagnetic slip clutch,smooth and efficient access to high speed characteristics.This method is suitable for the production does not require variable speed machinery, such as metal cutting machine Bed , Lift , Lifting equipment, Fans Water Pump And so on.2, Frequency Control Method Frequency control is to change the motor stator Power supply Frequency, thus changing the speed of its synchronous speed method. Frequency control system main equipment is to provide variable frequency power supply Inverter , Inverter can be divided into AC - DC - AC inverter and AC - AC converter two categories, most of the current domestic use of AC - DC - AC inverter. Its characteristicsHighefficiency, speed the process without additional loss;Wide range of applications, can be used for cage induction motor;Speed range, features a hard, high accuracy;Technical complexity, high cost, difficult maintenance and overhaul.This method is suitable for the high accuracy, good speed performance occasions.3, cascade control method Cascade control is wound into the rotor circuit in the series of additional potential can be adjusted to change the motor's slip, to achieve speed control purposes. Most of the deterioration in power to be in series with the added potential absorbed, re-use generate additional devices to absorb the deterioration in power to return power to use or conversion of energy. Slip-power absorption under way, cascade control can be divided into Motor Cascade control, mechanical and thyristor cascade control cascade control, and multi-use cascade control thyristor, characterized byCan speed the process of deterioration in loss of feedback to the network or productionmachinery, more efficient;Installed capacity and speed range in direct proportion to investment, applicable speed range 70% -90% rated speed of production machinery;peed device failure can switch to full speed, to avoid the cut-off;Thyristor cascade speed low power factor, harmonics greater impact.This method is suitable for fans, pumps and rolling mills, mine hoist, extrusion machines.4, wound rotor motor speed control method of Series ResistanceWound Rotor Motor additional resistance in series, so that the motor slip up, motor running at low speed. The greater the resistance in series, the motor speed is lower. This method is simple, easy to control, but deteriorate the power consumption in the form of heat in the resistor. Is a class speed, soft mechanical properties.5, the stator pressure and speed adjustment methodStator voltage when changing the motor, you can get a different set of mechanical properties of curves, which were different speeds. Since the motor torque and voltage proportional to the square, the largest decline in a lot of torque, speed range of its small cage motors in general and difficult to apply. In order to expand the speed range, pressure and speed adjustment should be larger rotor resistance value cage motors, such as dedicated voltage regulator with speed torque motor, or series wound motor frequency sensitive resistors. In order to expand the range of stable operation, when the speed of 2:1 or more occasions in the feedback control should be adopted to achieve the purpose of automatic adjustment of speed.Pressure and speed adjustment is a key device to provide power supply voltage, the current way of a tandem common saturation voltage regulator Reactor , Auto Transformer And several other Thyristor Surge. Thyristor Surge is the best way. Adjusting Speed featuresPressure and speed adjustment circuit is simple, easy to realize automatic control;Poor power surge process to heat transfer in the rotor resistance in the form of consumption, low efficiency.Pressure and speed adjustment generally applies to 100KW below production machinery.6.electromagnetic speed regulating motor speed control method of electromagneticspeed regulating electric motor squirrel cage motor, electric slip clutch and DC excitation power supply (Controller) consists of three parts. DC excitation power small, usually consisting of single phase half-wave or full wave rectifiers thyristors composition, change thyristor conduction angle, you can change the magnetizing current size.Electromagnetic slip clutch armature, poles and excitation windings composed of three parts. Armature and the latter has no mechanical contact, are free to rotate. Armature motor coaxial connection active part, driven by motors; docking with the load axis magnetic pole coupling from the moving parts. When the armature poles are at rest, such as excitation windings for DC, along the circumferential surface will form a number of air gap on the n, s, of alternating polarity poles, the magnetic flux through the armature. Dang electric armature with drag motor rotating Shi, due to electric armature and pole between relative movement, and makes electric armature induction produced Eddy, this Eddy and magnetic pass mutual role produced go moments, led has pole of rotor by same direction rotating, but its speed constant below electric armature of speed N1, this is a go difference adjustable speed way, changes go difference clutch device of DC Lai magnetic current, will can change clutch device of output go moments and speed. Characteristics of electromagnetic speed regulating motor speed:appliances, structure and control circuit is simple, reliable operation, easymaintenance; speed and smooth, stepless speed regulationthe power network harmonic effects;lost speed, low efficiency.This method applies to medium and small power, requires low speed when the smooth, short run production machinery.7. the hydraulic coupler speed regulating hydraulic Coupler is a device for hydraulic drive, is made up of the pump and turbine, they collectively work wheels, placed in a sealed case. Shell filled with a certain amount of working fluid, when pump is impulse driven by rotation, in which liquid propelled by blades which rotate, and under the action of centrifugal force along the outer wheels when entering the turbine pump, to thrust to the turbine blades on the same turn, make it drive production machinery running. Power transfer capacity of the hydraulic coupler and shell filled with fluid volume sizes are consistent. In the course of work, changing the filling rate can change the coupler of turbine speed, stepless speed regulation, characterized by:power scope, can meet the needs of from a couple of different power 10-kilowattto shuqianqian;simple structure, reliable performance, easy to operation and maintenance, andlow cost;small size, capacity;easy to adjust, easy to fulfill automatic control.This method applies to the speed of the fan and water pump.三相异步电动机的几种调速方式三相异步电动机转速公式为：n=60f/p(1-s)从上式可见，改变供电频率f、电动机的极对数p及转差率s均可太到改变转速的目的。