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毕业设计论文外文文献翻译基于PLC双电源开关设计外文翻译中英文对照

毕业设计论文外文文献翻译基于PLC双电源开关设计外文翻译中英文对照英文题目 Based on PLC dual power switch design 中文题目基于PLC双电源开关设计系 (院) 自动化系专业电气自动化技术滨州学院专科毕业设计(外文翻译)Intelligent double power1 Intelligent dual power supply switching technologyIn this paper, the double load - dual power automatic switching of PLC control, PLC control program to replace relay logic control circuits, it has the three-phase power supply phase detection and protection switching function, power returned to normal after the automatic reverse switch, when a fault and restore normal respectively sends out two difference clear alarm and prompt sound. Double load - dual power automatic switching control of PLC, the open-phase protection mainly adopts the technical proposal that : setting the three-phase open-phase detection signal circuit, the three-phase open-phase detection signal circuit directly from the main circuit of three-phase power supply, namely the intermediate relay KA1-KA3 and KA4-KA6, respectively connected to power supply main loop U1 and U2 A, B and C single phase circuit, KA1-KA3 and KA4-KA6 normally open contacts respectively as PLCinput signal, namely as the preparation of PLC U1 and U2 three-phase open-phase detection logic control program input conditions. With short phase protection double load - dual power automatic switching control, not only has the open-phase protection, but also has a short circuit and overload protection, under-voltage protection function; automatic phase lack detection, three-phase current display, a road power supply circuit can automatically switch to another power source to load power supply, light and sound alarm; in the power supply return to normal after automatic reverse switch; in the event of a failure and return to normal when respectively sends out two difference obvious alarm and prompt sound effects. It overcomes the shortcomings of low double power supply switching control system without phase protection, can automatically reverse switch, as well as fault and return to normal when using asingle audio prompts defects. The control system has perfect function, reliable performance, simple circuit structure, low manufacturing cost etc...2 Intelligent dual power supplies switching main circuit controlWith short phase protection double load - dual power automatic switching control circuit. It includes a main circuit and three-phase short signal detecting sampling circuit. The main circuit of the input power supply power supply U1 and U2, its output has two2滨州学院专科毕业设计(外文翻译)loads W1 and W2. Power main circuit of AC contactor U1 through KM1 main contacts and a load of W1 connected; power supply U2 main circuit through the AC contactor KM2 main contacts and a load of W2 connected; under the control of a control circuit, a power failure occurs, the AC contactor lost the first electrically disconnected, so that the load of detachment faults power supply circuit, the AC contactor KM3 main contact closing conduction contact loop, will be connected to the fault loop load switch automatically to another normal power supply continues to supply. Power supply U1 and U2 main circuit input end of the automatic switch in QF1 and QF2 is the primary role of overload protection and short-circuit protection; two phase power supply main loop in each phase are current meter to indicate the phase current status, with the control circuit of phase lack detection. The three-phase open-phase detection signal sampling circuit, the phase detection signal directly from the main circuit of three-phase power supply, namely the intermediate relay KA1 ~ KA3KA4 ~ KA6 are respectively connected to the power supply main loop U1 and U2 A, B phase and C phase of the single-phase circuit, KA1 ~ KA3 and KA4 ~ KA6 normally open contact as U1 and U2 three-phase open-phase detection switch sampling signal, to the PLC input terminal. Considering the PLC relay output point load capacity, through the contactor KM01 ~ KM03 to drive high current contactor KM1 ~ KM3.For three-phase power U1 A, B phase and C phase lack detection, the use of an intermediate relay KA1, KA2 and KA3, respectively connected topower the U1 main circuit A, B phase and C phase and zero line N constitute a single-phase circuit, the formation of A1, B1 and C1 phase detection circuit. The normally open contact of KA1 ~ KA3 as U1 three-phase.Phase lack detection switch sampling signal, to the PLC input terminal, used in the preparation of PLC U1 three-phase open-phase detection logic control program input conditions; similarly, the three-phase power supply U2 A, B phase and C phase lack detection, but also the use of an intermediate relay KA4, KA5 and KA6, respectively connected to power the U2 main circuit A2, B2 phase and C2 phase and zero line N constitute a single-phase circuit, the formation of A2, B2 and C2 three-phase open-phase detection circuit. KA4 ~ KA6 normally open contacts respectively as U2 three-phase open-phase detection switch sampling signal, to the PLC input terminal, used in the3滨州学院专科毕业设计(外文翻译)preparation of PLC U2 three-phase open-phase detection logic control program input conditions.3 With PLC intelligent dual power controlThe three-phase open-phase detection signal sampling circuit, as U1 and U2 three-phase open-phase detection switch sampling signals of KA1-KA3 and KA4-KA6, the normally open contacts respectively for the input of the PLC X0-X2, X3-X5. In the PLC ladder diagram program, auxiliary relay R1 as the three-phase power supply of U1 three-phase open-phasedetection, which is normally open input conditions for X0, X1 and X2" and" logic; similarly, internal intermediate relay R2 as the three-phase power supply of U2 three-phase open-phase detection, it’s on conditions for the normally open input X3, X4 and X5" and" logic.In automatic switching control process, PLC ladder diagram procedure of auxiliary relay R1 and R2 respectively controlled AC contactor KM1 ( Y0 ) and KM2 ( Y1 ) coil and electric state, directly reflects two three-phase power supply U1 and U2 respectively the total phase condition, namely, either U1 or U2 three-phase power supply phase, KM1 ( Y0 ) or KM2 ( Y1 ) will immediately loses electricity, the normally closed contact of the alternating current contactor closed KM3 ( Y2 ) control coil gets electricity to attract, through the KM3 main contacts closed conduction contact loop, will be connected to the fault circuit load W1 or W2 automatically switches to a normal power supply U2 or U1 to power supply, so as to realize open-phase protection automatic switching. In automatic switching control process, auxiliary relay R1 and R2 main function is: when troubleshooting, three-phase power U1 orU2 recover the normal power supply, R1 (or R2) have electricity, the normally closed contact action, R3 reset, cut KM3 (Y2), then KM1 (Y0) or KM1 (Y1) complex have electricity, thereby automatically reverse switching back to the power supply to load W1 U1, U2 W2 power supply to load the normal power supply state.The control circuit adopts electric whistle (or buzzer) as an alarm sound (at) the same time with the red signal (at the same time with thered signal lamp), and returned to normal when the bell HA as prompt sound. Can produce two distinct alarms and prompt sound effects.4滨州学院专科毕业设计(外文翻译)智能双电源1 智能双电源切换的技术方案本文所述的双负载—双电源自动切换的PLC控制,用PLC控制程序取代继电器逻辑控制电路,其具有对三相供电电源的缺相检测及保护切换功能,在电源恢复正常后能自动进行反切换,当发生故障和恢复正常时能分别发出两种区别明显的报警和提双负载—双电源自动切换的PLC控制,其缺相保护主要采取的技术方案是:示音响。

《功率因数校正开关电源的研究与设计》外文翻译

《功率因数校正开关电源的研究与设计》外文翻译Switching Power Supply Design(开关电源设计)CHAPTER 3Half- and Full-BridgeConverter Topologies3.1 IntroductionHalf-bridge and full-bridge topologies stress their transistors to a voltage equal to the DC input voltage not to twice this value, as do the push-pull, single-ended, and interleaved forward converter to pologies. Thus the bridge topologies are used mainly in offline converters where supply voltage would be more than the switching transistors could safely tolerate. Bridge topologies are almost always used where the normal AC input voltage is 220 V or higher, and frequently even for 120-V AC inputs.An additional valuable feature of the bridge topologies is that primary leakage inductance spikes (Figures 2.1 and 2.10) are easily clamped to the DC supply bus and the energy stored in the leakage inductance is returned to the input instead of having to be dissipated in a resistive snub -ber element.3.2 Half-Bridge Converter Topology3.2.1 Basic OperationHalf-bridge converter topology is shown in Figure 3.1. Its majoradvantage is that, like the double-ended forward converter, it subjects the “off” transistor to only V dc and not twice that value. Thus it is widely used in equipment intended for the European market, where the AC input voltage is 220 V. First consider the input rectifier and filter in Figure 3.1. It is used universally when the equipment is to work from either120-VACAmerican power or 220-V AC European power. The circuit always yields roughly320-V rectified DC voltage, whether the input is 120 orFIGURE 3.1 Half-bridge converter. One end of the power transformer primary is connected to thejunction of filter capacitors C1, C2 via a small DC locking capacitor Cb . The other end is connected to the junction of Q1, Q2, which turn “on” and “off” on alternate half cycles. With S1 in the closed position, the circuit is a voltage doubler ; in the open position, it is a full-wave rectifier. In either case, the rectified output is about 308 to 336 V dc.220 V AC. It does this when switch S1 is set to the open position for220-V AC input, or to the closed position for 120-V AC input. The S1 component is normally not a switch; more often it is a wire link that is either installed for 120 V AC, or not for 220 V AC.With the switch in the open 220-V AC position the circuit is a full wave rectifier, with filter capacitors C1 and C2 in series. It produces a peak rectified DC voltage of about (1.41×220) −2 or 308 V. When the switch is in the closed 120-V AC position , the circuit acts as a voltage doubler. One half cycle of the input voltage when A is positive relativeto B, C1 is charged positively via D1 to a peak of (1.41 ×120) −1 or 168 V. On a half cycle when A is negative with respect to B, capacitor C2 is charged positively via D2 to 168 V. The total voltage across C1 and C2 in series is then 336 V. It can be seen in Figure 3.1 that with either transistor “on,” the “off” transistor is subjected to the maximum DC input voltage and not twice that value. Since the topology subjects the “off” transistor to only Vdc and not 2Vdc, there are many inexpensive bipolar and MOSFET transistors that can support the nominal 336 DC V plus 15% upper maximum of 386 V. Thus the equipment can be used with either 120- or 220-V AC line inputs by making a simple switch or linkage change.Assuming a nominal rectified DC voltage of 336 V, the topology works asfollows: For the moment, ignore the small series blocking capacitor Cb . Assume the bottom end of Np is connected to the junction of C1 and C2. Then if the leakages in C1, C2 are assumed to be equal, that point will be at half the rectified DC voltage, about 168 V. It is generally good practice to place equal bleeder resistors across C1 and C2 to equalize their voltage drops. Now Q1 and Q2 conduct on alternate half cycles. When Q1 is “on” and Q2 “off” (Figure 3.1), the dot end of Np is 168 V positive with respect to itsno-dot end, and the “off” stress on Q2 is only 336 V. When Q2 is “on” andQ1 “off,” the dot end of Np is 168 V negative with respect to its no-dot end and the emitter of Q1 is 336 V negative with respect to its collector.This AC square-wave primary voltage produces full-wave squareWave-shapes on all second-aries—exactly like the secondary voltages in the push-pull topology. The selection of secondary voltages and wire sizes and the output inductor and capacitor proceed exactly as for the push-pull circuit.3.2.2 Half-Bridge Magnetics3.2.2.1 Selecting Maximum “On”Time, Magnetic Core,and Primary TurnsIt can be seen in Figure 3.1, that if Q1 and Q2 are “on” simultaneously—even for a very short time—there is a short circuit across the supply voltage and the transistors will be destroyed. To make sure that this does not happen, the maximum Q1 or Q2 “on” time, which occurs at minimum DC supply voltage, will be set at 80% of a half period. The secondary turns will be chosen so thatthe desired output voltages are obtained with an “on” time of no more than 0.8T/2. An “on”-time clamp will be provided to ensure that the “on” time can never be greater than 0.8T/2 under fault or transient conditions.The core is selected from the tables in Chapter 7 mentioned earlier. These tables give maximum available output power as a function of operating frequency, peak flux density, core and iron areas, and coil current density.With a core selected and its iron area known, the number of primary turns is calculated from Faraday’s law (Eq. 1.17) using the minimum primary voltage (Vdc/2) −1, and the maximum “on” time of 0.8T/2. Here, the flux excursion dB in the equation is twice the desired peak flux density (1600 G below 50 kHz, or less at higher frequency), because the half-bridge core operates in the first and third quadrants of its hysteresis loop—unlike the forward converter (Section 2.3.9), which operates in the first quadrant only.3.2.2.2 The Relation Between Input Voltage,Primary Current, and Output PowerIf we assume an efficiency of 80%, thenPin = 1.25PoThe input power at minimum supply voltage is the product of minimum primary voltage and average primary current at minimum DC input. At minimum DC input, the maximum “on” time in each half period will be set at 0.8T/2 as discussed above, and the primary has two current pulses of width0.8T/2 per period T. At primary voltage Vdc/2, the input power is 1.25Po = (Vdc/2)( Ipft)(0.8T/T),where Ipft is the peak equivalent flat-topped primary current pulse. ThenIpft (half bridge) = 3.13P0/Vdc(3.1)3.2.2.3 Primary Wire Size SelectionPrimary wire size must be much larger in a half bridge than in a push-pull circuit of the same output power. However, there are two half primaries in the push-pull, each of which has to support twice the voltage of the half-bridge primary when operated from the same supply voltage. Consequently, coil sizes for the two topologies are notmuch different. Half-bridge primary RMS current isIrms = Ipftand from Eq. 3.1Irms = 2.79Po/Vdc (3.2)At 500 circular mils per RMS ampere, the required number of circular mils is Circular mils needed = 500 ×2.79Po/Vdc= 1395Po/Vdc (3.3)3.2.2.4 Secondary Turns and Wire Size SelectionIn the following treatment the number of secondary turns will be selected using Eqs. 2.1 to 2.3 for Ton = 0.8T/2, and the term Vdc –1 will be replaced by theminimumprimary voltage, which is (Vdc/2)−1. The secondary RMScurrents and wire sizes are calculated from Eqs. 2.13 and 2.14, exactly as for the full-wave secondaries of a push-pull circuit.3.2.3 Output Filter CalculationsThe output inductor and capacitor are selected using Eqs. 2.20 and 2.22 as in a push-pull circuit for the same inductor current ramp amplitude and desired output ripple voltage.3.2.4 Blocking Capacitor to AvoidFlux ImbalanceTo avoid the flux-imbalance problem discussed in connection with the push-pull circuit (Section 2.2.5), a small capacitor Cb is fitted in series with the primary as in Figure 3.1. Recall that flux imbalance occurs if thevolt-second product across the primary while the core is set (moves in one direction along the hysteresis loop) differs from the volt-second product after it moves in the opposite direction. Thus, if the junction of C1 and C2 is not at exactly half the supply voltage, the voltage across the primary when Q1 is “on” will differ from the voltage across it when Q2 is “on” and the core will walk up or down the hysteresis loop, eventually causing saturation and destroying the transistors.This saturating effect comes about because there is an effective DC current bias in the primary. To avoid this DC bias, the blocking capacitor is placed in series in the primary. The capacitor value is selectedFIGURE 3.2 The small blocking capacitor Cb in series with the half-bridge primary (Figure 3.1) is needed to prevent flux imbalance if the junction of the filter capacitors is not at exactly the midpoint of the supply voltage. Primary current charges the capacitor, causing a droop in the primary voltage waveform. This droop should be kept to no more than 10%. (The droop in primary voltage, due to the offset charging of the blocking capacitor, is shown as dV.) as follows. The capacitor charges up as the primary current Ipft flows into it, robbing voltage from the flat-topped primary pulse shown in Figure 3.2.This DC offset robs volt-seconds from all secondary windings and forces a longer “on” time to achiev e the desired output voltage. In general, it is desirable to keep the primary voltage pulses as flat-topped as possible.In this example, we will assume a permissible droop of dV. The equivalent flat-topped current pulse that causes this droop is Ipft in Eq. 3.1. Then, because that current flows for 0.8T/2, the required capacitor magnitude is simplyCb = (3.4) Consider an example assuming a 150-W half bridge operating at 100 kHz from a nominal DC input of 320 V. At 15% low line, the DC input is 272 V and the primary voltage is ±272/2 or ±136V.A tolerable droop in the flat-topped primary voltage pulse wouldbe 10% or about 14 V.Then fromEq. 3.1 for 150Wand Vdc of 272V, Ipft =3.13×150/272= 1.73 A, and from Eq. 3.4, Cb = 1.73 ×0.8 ×5 ×10−6/14 = 0.49 F. The capacitor must be a nonpolarized type.3.2.5 Half-Bridge LeakageInductance ProblemsLeakage inductance spikes, which are so troublesome in the singleended forward converter and push-pull topology, are easily avoided in the half bridge: they are clamped to Vdc by the clamping diodes D5, D6 across transistors Q1, Q2.Assuming Q1 is “on,” the load and magnetizing currents flow through it and through the primary leakage inductance of T1, the paralleled T1 magnetizing inductance, and the secondary load impedances that are reflected by their turn ratios squared into the primary. Then it flows through Cb into the C1, C2 junction. The dot end of Np is positive with respect to its no-dot end.When Q1 turns “off,” the magnetizing indu ctance forces all winding polarities to reverse. The dot end of T1 starts to go negative by flyback action, and if this were to continue, it would put more than Vdc across Q1 and could damage it. Also, Q2 could be damaged by imposing a reverse voltage across it. However, the dot end of T1 is clamped by diode D6 to the supply rail Vdc and can go no more negative than the negative end of the supply.Similarly, when Q2 is “on,” it stores current in the magnetizinginductance, and the dot end of Np is negative with respect to the no-dot end (which is close to Vdc/2). When Q2 turns “off,” the magnetizing inductance reverses all winding polarities by flyback action and the dot end of Np tries to go positive but is caught at Vdc by clamp diode D5. Thus the energy stored in the leakage inductance during the “on” time is returned to the supply rail Vdc via diodes D5, D6.译文：第三章半桥和全桥变换器拓扑3.1 概述半桥和全桥拓扑开关管的稳态关断电压等于直流输入电压，而不像推挽、单端正激或交错正激拓扑那样为电压的两倍。

电磁干扰开关电源中英文对照外文翻译文献

(文档含英文原文和中文翻译)中英文翻译外文资料（原文）Modeling, Simulation, and Reduction of Conducted Electromagnetic Interference Due to a PWM Buck Type Switching Power Supply IAbstract:Undesired generation of radiated or conducted energy in electrical systems is called Electromagnetic Interference (EMI). High speed switching frequency in power electronics converters especially in switching power supplies improves efficiency but leads to EMI. Different kind of conducted interference, EMI regulations and conducted EMI measurement are introduced in this paper. Compliancy with national or international regulation is called Electromagnetic Compatibility (EMC). Power electronic systems producers must regard EMC. Modeling and simulation is the first step of EMC evaluation. EMI simulation results due to a PWM Buck type switching power supply are presented in this paper. To improve EMC, some techniques are introduced and their effectiveness proved by simulation.Index Terms:Conducted, EMC, EMI, LISN, Switching SupplyI. INTRODUCTIONFAST semiconductors make it possible to have high speed and high frequency switching in power electronics []1. High speed switching causes weight and volume reduction of equipment, but some unwanted effects such as radio frequency interference appeared []2. Compliance with electromagnetic compatibility (EMC) regulations is necessary for producers to present their products to the markets. It is important to take EMC aspects already in design phase []3. Modeling and simulation is the most effective tool to analyze EMC consideration before developing theproducts. A lot of the previous studies concerned the low frequency analysis of power electronics components []4[]5. Different types of power electronics converters are capable to be considered as source of EMI. They could propagate the EMI in both radiated and conducted forms. Line Impedance Stabilization Network (LISN) is required for measurement and calculation of conducted interference level []6. Interference spectrum at the output of LISN is introduced as the EMC evaluation criterion []7[]8. National or international regulations are the references for the evaluation of equipment in point of view of EMC []7[]8. II. SOURCE, PATH AND VICTIM OF EMIUndesired voltage or current is called interference and their cause is called interference source. In this paper a high-speed switching power supply is the source of interference.Interference propagated by radiation in area around of an interference source or by conduction through common cabling or wiring connections. In this study conducted emission is considered only. Equipment such as computers, receivers, amplifiers, industrial controllers, etc that are exposed to interference corruption are called victims. The common connections of elements, source lines and cabling provide paths for conducted noise or interference. Electromagnetic conducted interference has two components as differential mode and common mode []9.A. Differential mode conducted interferenceThis mode is related to the noise that is imposed between different lines of a test circuit by a noise source. Related current path is shown in Fig. 1 []9. The interference source, path impedances, differential mode current and load impedance are also shown in Fig. 1.B. Common mode conducted interferenceCommon mode noise or interference could appear and impose between the lines, cables or connections and common ground. Any leakage current between load and common ground could be modeled by interference voltage source.Fig. 2 demonstrates the common mode interference source, commonmode currents Icm1 and Icm2and the related current paths[]9.The powerelectronics converters perform as noise source between lines of the supply network. In this study differential mode of conducted interferenceis particularly important and discussion will be continued considering this mode only.III. ELECTROMAGNETIC COMPATIBILITY REGULATIONSApplication of electrical equipment especially static power electronic converters in different equipment is increasing more and more. As mentioned before, power electronics converters are considered as an important source of electromagnetic interference and have corrupting effects on the electric networks []2. High level of pollution resulting from various disturbances reduces the quality of power in electric networks. On the other side some residential, commercial and especially medical consumers are so sensitive to power system disturbances including voltage and frequency variations. The best solution to reduce corruption and improve power quality is complying national or international EMCregulations. CISPR, IEC, FCC and VDE are among the most famous organizations from Europe, USA and Germany who are responsible for determining and publishing the most important EMC regulations. IEC and VDE requirement and limitations on conducted emission are shown in Fig. 3 and Fig. 4 []7[]9.For different groups of consumers different classes of regulations could be complied. Class A for common consumers and class B with more hard limitations for special consumers are separated in Fig. 3 and Fig. 4. Frequency range of limitation is different for IEC and VDE that are 150 kHz up to 30 MHz and 10 kHz up to 30 MHz respectively. Compliance of regulations is evaluated by comparison of measured or calculated conducted interference level in the mentioned frequency range with the stated requirements in regulations. In united European community compliance of regulation is mandatory and products must have certified label to show covering of requirements []8.IV. ELECTROMAGNETIC CONDUCTED INTERFERENCE MEASUREMENTA. Line Impedance Stabilization Network (LISN)1-Providing a low impedance path to transfer power from source to power electronics converter and load.2-Providing a low impedance path from interference source, here power electronics converter, to measurement port.Variation of LISN impedance versus frequency with the mentioned topology is presented in Fig. 7. LISN has stabilized impedance in the range of conducted EMI measurement []7.Variation of level of signal at the output of LISN versus frequency is the spectrum of interference. The electromagnetic compatibility of a system can be evaluated by comparison of its interference spectrum with the standard limitations. The level of signal at the output of LISN in frequency range 10 kHz up to 30 MHz or 150 kHz up to 30 MHz is criterion of compatibility and should be under the standard limitations. In practical situations, the LISN output is connected to a spectrum analyzer and interference measurement is carried out. But for modeling and simulation purposes, the LISN output spectrum is calculated using appropriate software.外文资料（译文）基于压降型PWM开关电源的建模、仿真和减少传导性电磁干扰摘要：电子设备之中杂乱的辐射或者能量叫做电磁干扰(EMI)。

信息工程专业基于单片机的开关电源大学毕业论文外文文献翻译及原文

毕业设计（论文）外文文献翻译文献、资料中文题目：基于单片机的开关电源文献、资料英文题目：文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：信息工程班级：姓名：学号：指导教师：翻译日期： 2017.02.14本科毕业设计(论文)外文参考文献译文及原文学院信息工程学院专业信息工程年级班别学号学生姓名指导教师目录译文 (1)基于单片机的开关电源 (1)1、用途 (1)2、简介 (1)3、分类 (2)4、开关电源的分类 (3)5、技术发展动向 (4)6、原理简介 (6)7、电路原理 (7)8、DC/DC变换 (8)9、AC/DC变换 (8)原文 (10)The design Based onsingle chip switching power supply (10)1、uses (10)2、Introduction (10)3、classification (11)4、the switching power supply. (13)5、technology developments (14)6、the principle of Introduction (17)7、the circuit schematic (18)8、the DC / DC conversion (19)9, AC / DC conversion (20)译文基于单片机的开关电源1、用途开关电源产品广泛应用于工业自动化控制、军工设备、科研设备、LED 照明、工控设备、通讯设备、电力设备、仪器仪表、医疗设备、半导体制冷制热、空气净化器，电子冰箱，液晶显示器，LED灯具，通讯设备，视听产品，安防，电脑机箱，数码产品和仪器类等领域。

2、简介随着电力电子技术的高速发展，电力电子设备与人们的工作、生活的关系日益密切，而电子设备都离不开可靠的电源，进入80年代计算机电源全面实现了开关电源化，率先完成计算机的电源换代，进入90年代开关电源相继进入各种电子、电器设备领域，程控交换机、通讯、电子检测设备电源、控制设备电源等都已广泛地使用了开关电源，更促进了开关电源技术的迅速发展。

外文翻译：智能开关电源

Intelligent switch power supply英文：With the rapid development of electronic technology, application field of electronic system is more and more extensive, electronic equipment, there are more and more people work with electronic equipment, life is increasingly close relationship. Any electronic equipment are inseparable from reliable power supply for power requirements, they more and more is also high. Electronic equipment miniaturized and low cost in the power of light and thin, small and efficient for development direction. The traditional transistors series adjustment manostat is continuous control linear manostat. This traditional manostat technology more mature, and there has been a large number of integrated linear manostat module, has the stable performance is good, output ripple voltage small, reliable operation, etc. But usually need are bulky and heavy industrial frequency transformer and bulk and weight are big filter.In the 1950s, NASA to miniaturization, light weight as the goal, for a rocket carrying the switch power development. In almost half a century of development process, switch power because of its small volume, light weight, high efficiency, wide range, voltage advantages in electric, control, computer, and many other areas of electronic equipment has been widely used. In the 1980s, a computer is made up of all of switch power supply, the first complete computer power generation. Throughout the 1990s, switching power supply in electronics, electrical equipment, home appliances areas to be widely, switch power technology into the rapid development. In addition, large scale integrated circuit technology, and the rapid development of switch power supply with a qualitative leap, raised high frequency power products of, miniaturization, modular tide.Power switch tube, PWM controller and high-frequency transformer is an indispensable part of the switch power supply. The traditional switch power supply is normally made by using high frequency power switch tube division and the pins, such as using PWM integrated controller UC3842 + MOSFET is domestic small powerswitch power supply, the design method of a more popularity.Since the 1970s, emerged in many function complete integrated control circuit, switch power supply circuit increasingly simplified, working frequency enhances unceasingly, improving efficiency, and for power miniaturization provides the broad prospect. Three end off-line pulse width modulation monolithic integrated circuit TOP (Three switch Line) will Terminal Off with power switch MOSFET PWM controller one package together, has become the mainstream of switch power IC development. Adopt TOP switch IC design switch power, can make the circuit simplified, volume further narrowing, cost also is decreased obviouslyMonolithic switching power supply has the monolithic integrated, the minimalist peripheral circuit, best performance index, no work frequency transformer can constitute a significant advantage switching power supply, etc. American PI (with) company in Power in the mid 1990s first launched the new high frequency switching Power supply chip, known as the "top switch Power", with low cost, simple circuit, higher efficiency. The first generation of products launched in 1994 represented TOP100/200 series, the second generation product is the TOP Switch - debuted in 1997 Ⅱ. The above products once appeared showed strong vitality and he greatly simplifies thedesign of 150W following switching power supply and the development of new products for the new job, also, high efficiency and low cost switch power supply promotion and popularization created good condition, which can be widely used in instrumentation, notebook computers, mobile phones, TV, VCD and DVD, perturbation VCR, mobile phone battery chargers, power amplifier and other fields, and form various miniaturization, density, on price can compete with the linear manostat AC/DC power transformation module.Switching power supply to integrated direction of future development will be the main trend, power density will more and more big, to process requirements will increasingly high. In semiconductor devices and magnetic materials, no new breakthrough technology progress before major might find it hard to achieve, technology innovation will focus on how to improve the efficiency and focus onreducing weight. Therefore, craft level will be in the position of power supply manufacturing higher in. In addition, the application of digital control IC is the future direction of the development of a switch power. This trust in DSP for speed and anti-interference technology unceasing enhancement. As for advanced control method, now the individual feels haven't seen practicability of the method appears particularly strong,perhaps with the popularity of digital control, and there are some new control theory into switching power supply.（1）The technology: with high frequency switching frequencies increase, switch converter volume also decrease, power density has also been boosted, dynamic response improved. Small power DC - DC converter switch frequency will rise to MHz. But as the switch frequency unceasing enhancement, switch components and passive components loss increases, high-frequency parasitic parameters and high-frequency EMI and so on the new issues will also be caused.（2）Soft switching technologies: in order to improve the efficiency of non-linearity of various soft switch, commutation technical application and hygiene, representative of soft switch technology is passive and active soft switch technology, mainly including zero voltage switch/zero current switch (ZVS/ZCS) resonance, quasi resonant, zero voltage/zero current pulse width modulation technology (ZVS/ZCS - PWM) and zero voltage transition/zero current transition pulse width modulation (PWM) ZVT/ZCT - technical, etc. By means of soft switch technology can effectively reduce switch loss and switch stress, help converter transformation efficiency （3）Power factor correction technology (IC simplifies PFC). At present mainly divided into IC simplifies PFC technology passive and active IC simplifies PFC technology using IC simplifies PFC technology two kinds big, IC simplifies PFC technology can improve AC - DC change device input power factor, reduce the harmonic pollution of power grid.（4）Modular technology. Modular technology can meet the needs of the distributed power system, enhance the system reliability.（5）Low output voltage technology. With the continuous development of semiconductor manufacturing technology, microprocessor and portable electronic devices work more and more low, this requires future DC - DC converter can provide low output voltage to adapt microprocessor and power supply requirement of portable electronic devicesPeople in switching power supply technical fields are edge developing related power electronics device, the side of frequency conversion technology, development of switch between mutual promotion push switch power supply with more than two year growth toward light, digital small, thin, low noise and high reliability, anti-interference direction. Switching powersupply can be divided into the AC/DC and DC/DC two kinds big, also have AC/AC DC/AC as inverter DC/DC converter is now realize modular, and design technology and production process at home and abroad, are mature and standardization, and has approved by users, but the AC/DC modular, because of its own characteristics in the process of making modular, meet more complex technology and craft manufacture problems. The following two types of switch power supply respectively on the structure and properties of this.Switching power supply is the development direction of high frequency, high reliability, low consumption, low noise, anti-jamming and modular. Because light switch power, small, thin key techniques are changed, so high overseas each big switch power supply manufacturer are devoted to the development of new high intelligent synchronous rectifier, especially the improvement of secondary devices of the device, and power loss of Zn ferrite (Mn) material? By increasing scientific and technological innovation, to enhance in high frequency and larger magnetic flux density (Bs) can get high magnetic under the miniaturization of, and capacitor is a key technology. SMT technology application makes switching power supply has made considerable progress, both sides in the circuitboard to ensure that decorate components of switch power supply light, small, thin. The high frequency switching power supply of the traditional PWM must innovate switch technology, to realize the ZCS ZVS, soft switch technology hasbecome the mainstream of switch power supply technical, and greatly improve the efficiency of switch power. For high reliability index, America's switch power producers, reduce by lowering operating current measures such as junction temperature of the device, in order to reduce stress the reliability of products made greatly increased.Modularity is of the general development of switch power supply trend can be modular power component distributed power system, can be designed to N + 1 redundant system, and realize the capacity expansion parallel. According to switch power running large noise this one defect, if separate the pursuit of high frequency noise will increase its with the partial resonance, and transform circuit technology, high frequency can be realized in theory and can reduce the noise, but part of the practical application of resonant conversion technology still have a technical problem, so in this area still need to carry out a lot of work, in order to make the technology to practional utilization.Power electronic technology unceasing innovation, switch power supply industry has broad prospects for development. To speed up the development of switch power industry in China, we must walk speed of technological innovation road, combination with Chinese characteristics in the joint development path, for I the high-speed development of national economy to make the contribution. The basic principle and component functionAccording to the control principle of switch power to classification, we have the following 3 kinds of work mode:1) pulse width adjustment type, abbreviation Modulation Pulse Width pulse width Modulation (PWM) type, abbreviation for. Its main characteristic is fixed switching frequency, pulse width to adjust by changing voltage 390v, realize the purpose. Its core is the pulse width modulator. Switch cycle for designing filter circuit fixed provided convenience. However, its shortcomings is influenced by the power switch conduction time limit minimum of output voltage cannot be wide range regulation; In addition, the output will take dummy loads commonly (also called pre load), in order to prevent the drag elevated when output voltage. At present, most ofthe integrated switch power adopt PWM way.2) pulse frequency Modulation mode pulse frequency Modulation (, referred to Pulse Frequency Modulation, abbreviation for PFM) type. Its characteristic is will pulse width fixed by changing switch frequency to adjust voltage 390v, realize the purpose. Its core is the pulse frequency modulator. Circuit design to use fixed pulse-width generator to replace the pulse width omdulatros and use sawtooth wave generator voltage？Frequency converter (for example VCO changes frequency VCO). It on voltage stability principle is: when the output voltage Uo rises, the output signal controller pulse width unchanged and cycle longer, make Uo 390v decreases, and reduction. PFM type of switch power supply output voltage range is very wide, output terminal don't meet dummy loads. PWM way and way of PFM respectively modulating waveform is shown in figure 1 (a), (b) shows, tp says pulse width (namely power switch tube conduction time tON), T represent cycle. It can be easy to see the difference between the two. But they have something in common: (1) all use time ratio control (TRC) on voltage stability principle, whether change tp, finally adjustment or T is pulse 390v. Although adopted in different ways, but control goals, is all rivers run into the sea. (2) when load by light weight, or input voltage respectively, from high changed by increasing the pulse width, higher frequency method to make the output voltage remained stable.3) mix modulation mode, it is to point to the pulse width and switching frequency is not fixed, each other can change, it belongs to the way the PWM and PFM blend mode. It contains a pulsewidthomdulatros and pulse frequency modulator. Because and T all can adjust alone, so occupies emptiescompared to adjust the most wide range, suitable for making the output voltage for laboratories that use a wide range of can adjust switching power supply. Above 3 work collectively referred to as "Time Ratio Control" (as a Control, from TRC) way. As noted, pulse width omdulatros either as a independent IC use (for example UC3842 type pulse width omdulatros), can also be integrated in DC/DC converter (for example LM2576 type switching voltage regulators integrated circuit), still can integration in AC/DC converter (for exampleTOP250 type monolithic integrated circuit switching power supply. Among them, the switching voltage regulators belong to DC/DC power converter, switching power supply general for AC/DC power converter.The typical structure of switch power as figure1shows, its working principle is: the first utility into power rectifier and filtering into high voltage dc and then through the switch circuit and high-frequency switch to high frequency low pressure pulse transformer, and then after rectification and filter circuits, finally output low voltage dc power. Meanwhile in the output parts have a circuit feedback to control circuit, through the control PWM occupies emptiescompared to achieve output voltage stability.Figure 1 typical structure of switch power supplySwitching power supply by these four components:1) the main circuit: exchange network input, from the main circuit to dc output. Mainly includes input filter, rectifier and filtering, inverter, and output rectifier and filtering.(1) input filter: its effect is the power grid existing clutter filtering, also hinder the machine produces clutter feedback to public power grid.(2) rectifier and filter: the power grid ac power directly for a smooth dc rectifier, for the next level transformation.(3) inverter: will the dc after rectifying a high-frequency ac, this is the core of high frequency switching power supply, the higher the frequency, the volume, weight and the ratio of power output and smaller.(4) Out put rectifier and filter: according to load needs, providing stable and reliable dc power supply. 2) control circuit: on the one hand, from the output bysampling with set standards to compare, and then to control inverter, changing its frequency or pulse width, achieve output stability, on the other hand, according to data provided by the test circuit, the protection circuit differential, provide control circuit to the machine to various protection measures. Including the output feedback circuit and sampling circuit, pulse width modulator. 3) the detection and protection circuit: detection circuit had current detection, over-voltage detection, owe voltage detection, overheat detection, etc.; Protection circuit can be divided over current protection, over-voltage protection, owe voltage protection, the ground-clamp protection, overheating protection, automatic restart, soft start, slow startup, etc. Various types. 4) Other circuit: if the sawtooth wave generator, offset circuit, optical coupler, etc.智能开关电源中文：随着电子技术的高速发展，电子系统的应用领域越来越广泛，电子设备的种类也越来越多，电子设备与人们的工作、生活的关系日益密切。

开关电源外文翻译()

开关电源外文翻译()————————————————————————————————作者：————————————————————————————————日期：Modeling, Simulation, and Reduction of Conducted Electromagnetic Interference Due to a PWM Buck Type Switching Power Supply IA. FarhadiAbstract:Undesired generation of radiated or conducted energy in electrical systems is called Electromagnetic Interference (EMI). High speed switching frequency in power electronics converters especially in switching power supplies improves efficiency but leads to EMI. Different kind of conducted interference, EMI regulations and conducted EMI measurement are introduced in this paper. Compliancy with national or international regulation is called Electromagnetic Compatibility (EMC). Power electronic systems producers must regard EMC. Modeling and simulation is the first step of EMC evaluation. EMI simulation results due to a PWM Buck type switching power supply are presented in this paper. To improve EMC, some techniques are introduced and their effectiveness proved by simulation.Index Terms:Conducted, EMC, EMI, LISN, Switching SupplyI. INTRODUCTIONFAST semiconductors make it possible to have high speed and high frequency switching in power electronics []1. High speed switching causes weight and volume reduction of equipment, but some unwanted effects such as radio frequency interference appeared []2. Compliance with electromagnetic compatibility (EMC) regulations is necessary for producers to present their products to the markets. It is important to take EMC aspects already in design phase []3. Modeling and simulation is the most effective tool to analyze EMC consideration before developing the products. A lot of the previous studies concerned the low frequency analysis of power electronics components []4[]5. Different types of power electronics converters are capable to be considered as source of EMI. They could propagate the EMI in both radiated and conducted forms. Line Impedance Stabilization Network (LISN) is required for measurement and calculation of conducted interference level []6. Interference spectrum at the output of LISN is introduced as the EMC evaluation criterion []7[]8. National or international regulations are the references for the evaluation of equipment in point of view of EMC []7[]8.II. SOURCE, PATH AND VICTIM OF EMIUndesired voltage or current is called interference and their cause is called interferencesource. In this paper a high-speed switching power supply is the source of interference.Interference propagated by radiation in area around of an interference source or by conduction through common cabling or wiring connections. In this study conducted emission is considered only. Equipment such as computers, receivers, amplifiers, industrial controllers, etc that are exposed to interference corruption are called victims. The common connections of elements, source lines and cabling provide paths for conducted noise or interference. Electromagnetic conducted interference has two components as differential mode and common mode []9.A. Differential mode conducted interferenceThis mode is related to the noise that is imposed between different lines of a test circuit by a noise source. Related current path is shown in Fig. 1 []9. The interference source, path impedances, differential mode current and load impedance are also shown in Fig. 1.B. Common mode conducted interferenceCommon mode noise or interference could appear and impose between the lines, cables or connections and common ground. Any leakage current between load and common ground could be modeled by interference voltage source.and Fig. 2 demonstrates the common mode interference source, common mode currents Icm1 and the related current paths[]9.The power electronics converters perform as noise source Icm2between lines of the supply network. In this study differential mode of conducted interference is particularly important and discussion will be continued considering this mode only.III. ELECTROMAGNETIC COMPATIBILITY REGULATIONS Application of electrical equipment especially static power electronic converters in different equipment is increasing more and more. As mentioned before, power electronics converters are considered as an important source of electromagnetic interference and have corrupting effects on the electric networks []2. High level of pollution resulting from various disturbances reduces the quality of power in electric networks. On the other side some residential, commercial and especially medical consumers are so sensitive to power system disturbances including voltage and frequency variations. The best solution to reduce corruption and improve power quality is complying national or international EMC regulations. CISPR, IEC, FCC and VDE are among the most famous organizations from Europe, USA and Germany who are responsible for determining and publishing the most important EMC regulations. IEC and VDE requirement and limitations on conducted emission are shown in Fig. 3 and Fig. 4 []7[]9.For different groups of consumers different classes of regulations could be complied. Class A for common consumers and class B with more hard limitations for special consumers are separated in Fig. 3 and Fig. 4. Frequency range of limitation is different for IEC and VDE that are 150 kHz up to 30 MHz and 10 kHz up to 30 MHz respectively. Compliance of regulations isevaluated by comparison of measured or calculated conducted interference level in the mentioned frequency range with the stated requirements in regulations. In united European community compliance of regulation is mandatory and products must have certified label to show covering of requirements []8.IV. ELECTROMAGNETIC CONDUCTED INTERFERENCE MEASUREMENTA. Line Impedance Stabilization Network (LISN)1-Providing a low impedance path to transfer power from source to power electronics converter and load.2-Providing a low impedance path from interference source, here power electronics converter, to measurement port.Variation of LISN impedance versus frequency with the mentioned topology is presented inFig. 7. LISN has stabilized impedance in the range of conducted EMI measurement []7.Variation of level of signal at the output of LISN versus frequency is the spectrum of interference. The electromagnetic compatibility of a system can be evaluated by comparison of its interference spectrum with the standard limitations. The level of signal at the output of LISN in frequency range 10 kHz up to 30 MHz or 150 kHz up to 30 MHz is criterion of compatibility and should be under the standard limitations. In practical situations, the LISN output is connected to a spectrum analyzer and interference measurement is carried out. But for modeling and simulation purposes, the LISN output spectrum is calculated using appropriate software.For a simple fixed frequency PWM controller that is applied to a Buck DC/DC converter, it is) changes slow with respect to the switching frequency, the possible to assume the error voltage (vepulse width and hence the duty cycle can be approximated by (1). Vp is the saw tooth waveform amplitude.A. PWM waveform spectral analysisThe normalized pulse train m (t) of Fig. 8 represents PWM switch current waveform. The nth pulse of PWM waveform consists of a fixed component D/fs , in which D is the steady state duty cycle, and a variable component dn/f sthat represents the variation of duty cycle due to variation of source, reference and load.As the PWM switch current waveform contains information concerning EMI due to powersupply, it is required to do the spectrum analysis of this waveform in the frequency range of EMI studies. It is assumed that error voltage varies around V e with amplitude of V e1 as is shown in (2).fm represents the frequency of error voltage variation due to the variations of source, reference and load. The interception of the error voltage variation curve and the saw tooth waveform with switching frequency, leads to (3) for the computation of duty cycle coefficients []10.Maximum variation of pulse width around its steady state value of D is limited to D1. In each period of Tm=1/fm , there will be r=fs/fm pulses with duty cycles of dn. Equation (4) presents the Fourier series coefficients Cn of the PWM waveform m (t). Which have the frequency spectrum of Fig.9.B-Equivalent noise circuit and EMI spectral analysisTo attain the equivalent circuit of Fig.6 the voltage source Vs is replaced by short circuit and) as it has shown in Fig. 10. converter is replaced by PWM waveform switch current (IexThe transfer function is defined as the ratio of the LISN output voltage to the EMI current source as in (5).The coefficients di, ni (i = 1, 2, … , 4) correspond to the parameters of the equivalent circuit. Rc and Lc are respectively the effective series resistance (ESR) and inductance (ESL) of the filter capacitor Cf that model the non-ideality of this element. The LISN and filter parameters are as follows: CN = 100 nF, r = 5 Ω, l = 50 uH, RN =50 Ω, LN=250 uH, Lf = 0, Cf =0, Rc= 0, Lc= 0, fs =25 kHzThe EMI spectrum is derived by multiplication of the transfer function and the source noise spectrum. Simulation results are shown in Fig. 11.VI. PARAMETERS AFFECTION ON EMIA. Duty CycleThe pulse width in PWM waveform varies around a steady state D=0.5. The output noise spectrum was simulated with values of D=0.25 and 0.75 that are shown in Fig. 12 and Fig. 13. Even harmonics are increased and odd ones are decreased that is desired in point of view of EMC.On the other hand the noise energy is distributed over a wider range of frequency and the level of EMI decreased []11.B. Amplitude of duty cycle variationThe maximum pulse width variation is determined by D1. The EMI spectrum was simulatedwith D1=0.05. Simulations are repeated with D1=0.01 and 0.25 and the results are shown in Fig.14and Fig.15.Increasing of D1 leads to frequency modulation of the EMI signal and reduction in level of conducted EMI. Zooming of Fig. 15 around 7th component of switching frequency in Fig. 16 shows the frequency modulation clearly.C. Error voltage frequencyThe main factor in the variation of duty cycle is the variation of source voltage. The fm=100 Hz ripple in source voltage is the inevitable consequence of the usage of rectifiers. The simulation is repeated in the frequency of fm=5000 Hz. It is shown in Fig. 17 that at a higher frequency for fm the noise spectrum expands in frequency domain and causes smaller level of conducted EMI. On the other hand it is desired to inject a high frequency signal to the reference voltage intentionally.D. Simultaneous effect of parametersSimulation results of simultaneous application of D=0.75, D1=0.25 and fm=5000 Hz that leadto expansion of EMI spectrum over a wider frequencies and considerable reduction in EMI level is shown in Fig. 18.VII. CONCLUSIONAppearance of Electromagnetic Interference due to the fast switching semiconductor devices performance in power electronics converters is introduced in this paper. Radiated and conducted interference are two types of Electromagnetic Interference where conducted type is studied in this paper. Compatibility regulations and conducted interference measurement were explained. LISN as an important part of measuring process besides its topology, parameters and impedance were described. EMI spectrum due to a PWM Buck type DC/DC converter was considered and simulated. It is necessary to present mechanisms to reduce the level of Electromagnetic interference. It shown that EMI due to a PWM Buck type switching power supply could be reduced by controlling parameters such as duty cycle, duty cycle variation and reference voltage frequency.VIII. REFRENCES[1] Mohan, Undeland, and Robbins, “Power Electronics Converters, Applications and Design” 3rdedition, John Wiley & Sons, 2003.[2] P. Moy, “EMC Related Issues for Power Electronics”, IEEE, Automotive Pow er Electronics, 1989, 28-29 Aug. 1989 pp. 46 – 53.[3] M. J. Nave, “Prediction of Conducted Interference in Switched Mode Power Supplies”, Session 3B, IEEE International Symp. on EMC, 1986.[4] Henderson, R. D. and Rose, P. J., “Harmonics and their Effec ts on Power Quality and Transformers”, IEEE Trans. On Ind. App., 1994, pp. 528-532.[5] I. Kasikci, “A New Method for Power Factor Correction and Harmonic Elimination in Power System”, Proceedings of IEEE Ninth International Conference on Harmonics and Q uality of Power, Volume 3, pp. 810 – 815, Oct. 2000.[6] M. J. Nave, “Line Impedance Stabilization Networks: Theory and Applications”, RFI/EMI Corner, April 1985, pp. 54-56.[7] T. Williams, “EMC for Product Designers” 3rd edition 2001 Newnes.[8] B. Ke isier, “Principles of Electromagnetic Compatibility”, 3rd edition ARTECH HOUSE 1987.[9] J. C. Fluke, “Controlling Conducted Emission by Design”, Vanhostrand Reinhold 1991.[10] M. Daniel,”DC/DC Switching Regulator Analysis”, McGrawhill 1988[11] M. J. Nave,” The Effect of Duty Cycle on SMPS Common Mode Emission: theory and experiment”, IEEE National Symposium on Electromagnetic Compatibility, Page(s): 211-216, 23-25 May 1989.作者：A. Farhadi国籍：伊朗出处：基于压降型PWM开关电源的建模、仿真和减少传导性电磁干扰IIA. Farhadi作者：A. Farhadi国籍：伊朗出处：摘要：电子设备之中杂乱的辐射或者能量叫做电磁干扰(EMI)。

微机开关电源的含义-毕业论文外文翻译

中英文翻译The meaning of computer switching power supplySwitching Power Supply is the use of modern power electronics, control transistors switch on and off the opening time rate, to maintain a stable output voltage power supplies, switching power supply from the general pulse width modulation (PWM) control IC and MOSFET pose. Linear power supply and switching power supply compared with the two costs are increasing output growth, but with different growth rate. Power costs in a linear output power point, but higher than the switching power supply, known as the cost of this reversal point. With the development of power electronics technology and innovation, making switching power supply technology has constantly innovative, cost reverse this point to the increasing output of low-power mobile, switching power supply to provide a broad space for development.High-frequency switching power supply is the direction of their development, so thathigh-frequency switching power supply of small, and switching power supply into a wider range of applications, particularly in the application of high-tech fields, and promote the high-tech products of small, lightweight Of. Also switching power supply in the development and application of energy conservation, resource conservation and environmental protection are of great significance. Switching Power Supply CategoryPeople in switching power supply side is the development of technology-related power electronic devices, while the development of frequency switching technology, the two promote each other to promote the switch power annually to more thantwo-digit growth in a light, small, lightweight, low noise, high reliability, Anti-jamming direction. Switching Power Supply can be divided into AC / DC and DC / DC two categories, DC / DC converter which is now modular, design and technology and production technology at home and abroad have been mature and standardized, and have been authorized users, but AC / DC modular, makes its own characteristics in the process of modular, encountered a more complex technology and manufacturing process problems. Following were the two types of switching power supply for the structure and characteristics to set out.1 DC/DC transformDC / DC is to transform the fixed DC voltage transformation into a variable DC voltage, also known as DC chopper. Chopper's work in two ways, first PWM Ts the same way, change ton (GM) and the second is the frequency modulation, ton unchanged, change Ts (easily interference). Their specific circuit from the following categories: (1) Buck circuit - buck chopper, the average output voltage U0 less than the input voltage Ui, the same polarity. (2) Boost circuit - Boost chopper, the average output voltage U0 greater than the input voltage Ui, the same polarity. (3) Buck-Boost circuit - buck or boost chopper, U0 average output voltage greater than or less than the input voltage Ui, polar opposite, inductance transmission. (4) Cuk circuit - buck or boost chopper, its average output power U0 pressure greater than or less than the input voltage Ui, polar opposite, capacitance transmission. Today's technology allows soft switching DC / DC has undergone a qualitative leap forward, the United States VICOR companies design and manufacture of a varietyof ECI soft-switching DC / DC converters, the largest of its power output is 300 W, 600W, 800W, the power density of the corresponding (6.2 , 10,17) W/cm3, efficiency (80 to 90)%. Japan's latest NemicLambda launched a soft-switch technology using high-frequency switching power supply module RM Series, the switches at (200 ~ 300) kHz, the power density has reached 27 W/cm3, using synchronous rectifier (MOS FET replace SCHOTT - Diode), the efficiency of the entire circuit to 90 percent.2 AC/DC transformAC / DC transformation is to transform exchange for DC, its power can be a two-way flow, the flow of power flow from the power load known as the "rectification", the power flow from the load to return to power as "active inverter." AC / DC converter for the importation of AC 50/60 Hz, due to the rectification, filtering, the relatively large size of the filter capacitor is essential, because encountered safety standards (such as UL, CCEE) and EMC Directive Restrictions (such as IEC,, FCC, CSA), AC input side and EMC filter must meet safety standards and the use of the components, such restrictions on the AC / DC power of the small size of the addition, since the internal high-frequency, high-pressure, big Current switching action, made the resolution of EMC difficult to electromagnetic compatibility problems, will install the internal high-density circuit design to the high demand for the same reason, high-voltage, high current power switches make greater loss of work, limiting the AC / DC converter modular process, it must be in power system design methods to optimize the efficiency of its work reaches a certain level of satisfaction.AC / DC transform the circuit can be divided into the connection mode, half-wave circuit,full-wave circuit. By the power of a few can be divided into, single-phase, three-phase, multi-phase. Circuit work on a quadrant can be divided into quadrants, the quadrant, the three-quadrant, the four quadrants. Selection of switching power supply3 Switching power supplyIn the importation of anti-jamming performance, as its own circuit of the characteristics of (multi-level series), the general importation of interference such as a surge through the difficult, in the output voltage stability of the technology indicators compared with the linear power Have greater advantages, its output voltage stability up (0.5 to 1)%. Switching power modules as a power electronic device integration, the choice should note the following: Because of the high efficiency switching power supply, can usually more than 80 percent, it was their choice of output current, accurate measurement of electrical equipment or calculating the maximum absorption current, so that was the choice of switching power supply has a high cost performance, Output is usually calculated as follows:Is = KIfType in: Is-switching power supply is rated output current;If-the largest electrical equipment absorb current; K-margin coefficient, from 1.5 to 1.8 in general;4 groundingLinear power than the power switch will generate more interference, the common mode interference sensitive electrical equipment, grounding and shielding should take measures, according to ICE1000, EN61000, FCC restrictions, such as EMC, switching power supply are taking measures EMC EMC, Switching power supply should normally with EMC EMC filter. If lied Huafu technology HA series switching power supply, its FG terminal users access to the land or the case in order to meet the electromagnetic compatibility requirements.protection circuit In switching power supply design must have a flow of overheating, such as short-circuit protection, it should be preferred in the design of the protection of the full-featured switch power modules, and its protection circuit with the technical parameters of the work of electrical equipment matched to Avoid damage to electrical equipment or switching power supply. Switching power supply technology development trends Switching Power Supply is the direction of development of high-frequency, high reliability, low consumption, low noise, interference and modular. Since switching power supply light, small, thin is the key technology of high-frequency, switching power supply major foreign manufacturers are committed to synchronize the development of new high-intelligent devices, particularly in the second rectifier of the loss and iron in power Oxygen-(Mn Zn) materials to increase the scientific and technological innovation, to enhance the high-frequency and larger magnetic flux density (Bs) under high magnetic properties, and the small capacitor is also a key technology. SMT technology applications makes switching power supply has made considerable progress, both sides of the circuit board layout components, to ensure that the light switch power, small, thin. The high-frequency switching power supply is bound to the tradition of the PWM switching technology innovation and achieve ZVS, ZCS the soft-switch technology has become the mainstream of switching power supply technology and a substantial increase in the switching power supply efficiency. For high-reliability indicators, the U.S. switching power supply manufacturers by reducing operating current, lower junction temperature devices, and other measures to reduce the stress, increased reliability greatly improved. Modular Switching Power Supply is the general trend of development, can be used modular power components distributed power systems, designed to N +1 redundant power systems, and parallel way to achieve the capacity expansion. Power switching operation for this big noise shortcomings, if the individual pursuit of its high-frequency noise will also increase with, and the use of the resonance conversion circuit technology, in theory, can achieve the high-frequency noise can be reduced, but some Resonant conversion of the practical application of technology there are still technical problems in this area is still a great deal of work to make the technology to practical use.Power electronics technology innovation, switching power supply industry has broad development prospects. China's switch to accelerate the pace of development of power industry, we must walk the road of technological innovation, out of production, study and research with Chinese characteristics, the joint development, for the rapid development of China's national economy to contribute.微机开关电源的含义开关电源是利用现代电力电子技术，控制开关晶体管开通和关断的时间比率，维持稳定输出电压的一种电源，开关电源一般由脉冲宽度调制（PWM）控制IC和MOSFET构成。

开关电源设计英文翻译

毕业设计(论文)外文资料翻译院（系）：电子信息工程学院专业：自动化班级：120427姓名：加如月学号：120406122外文出处：中国知网科技论文附件： 1.译文；2.原文；3.评分表2016年5 月Switching Power Supply DesignJ. M. LEISTEN , M. DOUBLE & L. HOBSONTo cite this article: J. M. LEISTEN , M. DOUBLE & L. HOBSON (1990) Switching Power Supply Designflyback , International Journal of Electronics, 69:3, 435-449, DOI:10.1080/00207219008920329To link to this article: /10.1080/00207219008920329Switching power supply work in high frequency, high pulse state, are analog circuits in a rather special kind. Cloth boards to follow the principle of high-frequency circuit wiring.yout:Pulse voltage connection as short as possible, including input switch connected to the transformer, output transformer to the rectifier tube cable. Pulse current loop as small as possible such as the input filter capacitor is returned to the transformer to the switch capacitor negative. Some out-ended output transformers are the output rectifier to the output capacitor back to transformer circuit X capacitor as close as possible to the input switching power supply, input lines should be avoided in parallel with other circuits, should be avoided. Y capacitor should be placed in the chassis ground terminal or FG connectors. A total of touch induction and transformer to maintain a certain distance in order to avoid magnetic coupling. Such as poor handling of feeling in between inductor and transformer plus a shield, over a number of EMC performance for power supply to the greater impact.General the output capacitor can be used the other two a close rectifier output terminal should be close to, can affect the power supply output ripple index, two small capacitor in parallel results should be better than using a large capacitor. Heating devices to maintain a certain distance, andelectrolytic capacitors to extend machine life, electrolytic capacitors is the switching power supply bottleneck life, such as transformers, power control, high power resistors and electrolytic to maintain the distance required between the electrolyte leaving space for heat dissipation , conditions permitting, may be placed in the inlet.Control part to pay attention to: Weak signal high impedance circuit connected to sample the feedback loop as short as in the processing as far as possible avoid interference, the current sampling signal circuits, in particular the current control circuit, easy to deal with some unexpected bad The accident, which had some skill, now to 3843 the circuit example shown in full time by observing the current waveform oscilloscope Mingxian superimposed spikes, Youyuganrao limited flow ratio design Zhi Dian low, Figure 1 there is no such phenomenon, there are switch drive signal circuit, switch resistance should be close to the switch driver can switch the work to improve the reliability of this and the high DC impedance voltage power MOSFET driver characteristics. Second, routingAlignment of current density: now the majority of electronic circuit board using insulated copper constitute tied. Common PCB copper thickness of 35μm, the alignment value can be obtained in accordance with 1A/mm experience the value of current density, the specific calculations can be found in textbooks. To ensure the alignment principles of mechanical strength should be greater than or equal to the width of 0.3mm (other non-power supply circuit board may be smaller minimum line width). PCB copper thickness of 70μm is also common in switching power supply, then the current density can be higher.Add that, now Changyong circuit board design tool design software generally items such as line width, line spacing, hole size and so dry plate Guo Jin Xing parameters can be set. In the design of circuit boards, design software automatically in accordance with the specifications, can save time, reduce some of the workload and reduce the error rate.Generally higher on the reliability of lines or line density wiring can be used double panel. Characterized by moderate cost, high reliability, to meet most applications.The ranks of some of the power module products are also used plywood, mainly to facilitate integration of power devices such as transformer inductance to optimize wiring, cooling and other power tube. Good consistency with the craft beautiful, transformer cooling good advantage, but its disadvantage is high cost, poor flexibility, only suitable for industrial mass production.Single-sided, the market circulation of almost universal switching power supply using single-sided circuit board, which has the advantage of lower costs in the design and production technology are also taken some measures to ensure its performance.Single PCB design today to talk about some experience, as a single panel with low cost, easy-to-manufacture features, the switching power supply circuit has been widely used, because of its side tied only copper, the device's electrical connections, mechanical fixation should rely on the copper layer, the processing must be careful.To ensure good performance of the mechanical structure welding, single-sided pad should be slightly larger to ensure that the copper and substrate tied good focus, and thus will not be shocked when the copper strip, broken off. General welding ring width should be greater than 0.3mm. Pad diameter should be slightly larger than the diameter of the device pins, but not too large, to ensure pin and pad by the solder connection between the shortest distance, plate hole size should not hinder the normal conditions for the degree of investigation, the pad diameter is generally greater than pin diameter 0.1-0.2mm. Multi-pin device to ensure a smooth investigation documents can also be larger.Electrical connection should be as wide as possible, in principle, should be larger than the width of pad diameter, special circumstances should be connected in line with the need to widen the intersection pad (commonly known as Generation tears), to avoid breaking certain conditions, line and pad. Principle of minimum line width should be greater than 0.5mm.Single-board components to be close to the circuit board. Need overhead cooling device to device and circuit board between the pins plus casing, can play a supporting device and increase the dual role of insulation to minimize or avoid external shocks on the pad and thepin junction impact and enhance the firmness of welding. Circuit board supporting the weight of large parts can increase the connection point, can enhance joint strength between the circuit board, such as transformers, power device heat sink.Single-sided welding pins without affecting the surface and the shell spacing of the prior conditions, it can be to stay longer, the advantage of increased strength of welded parts, increase weld area and immediately found a Weld phenomenon. Shear pin long legs, the welding force smaller parts. In Taiwan, the Japanese often use the device pins in the welding area and the circuit board was bent 45 degrees, and then welding process, its reasoning Ibid. Double panel today to talk about the design of some of the issues, in relatively high number of requests, or take the line density of the larger application environments using double-sided PCB, its performance and various indicators of a lot better than a single panel.Two-panel pad as holes have been high intensity metal processing, welding ring smaller than a single panel, the pad hole diameter slightly larger in diameter than pins, as in the welding process solder solution conducive to penetrate through the top hole solder pad to increase the welding reliability. But there is a disadvantage if the hole is too large, wave soldering tin when the jet impact in the lower part of the device may go up, have some flaws.High current handling of alignment, line width in accordance with pre-quote processing, such as the width is not enough to go online in general can be used to increase the thickness of tin plating solution, the method has a good variety of1. Will take the line set to pad property, so that when the circuit board manufacturing solder alignment will not be covered, the whole hot air normally be tin plated.2. In the wiring by placing pads, the pad is set to take in line shape, pay attention3. In the solder layer placed on line, this method is the most flexible, but not all PCB manufacturers will understand your intentions, needed captions. Place the line in the solder layer of the site will not coated solder tinning line several methods as above, to note that, if the alignment of a very wide all plated with tin in solder after thesolder will bond a lot and distribution is very uneven, affecting appearance. Article tin can be used generally slender width in the 1 ~ 1.5mm, length can be determined according to lines, tin part of the interval 0.5 ~ 1mmDouble-sided circuit board for the layout, the alignment provides a very selective, make wiring more reasonable. On the ground, the power ground and signal ground must be separated, the two to converge in filter capacitors, in order to avoid a large pulsed current through the signal ground connection instability caused by unexpected factors, the signal control circuit grounding point as far as possible, a skill, as far as possible the alignment of the non-grounded wiring layer in the same place, the last shop in another layer of earth. Output line through the filter capacitors, the general first, and then to the load, input line must also pass capacitor, to the transformer, the theoretical basis is to ripple through trip filter capacitor.V oltage feedback sampling, in order to avoid high current through the alignment of the feedback voltage on the sampling point must be the most peripheral power output to increase the load effect of target machine.Alignment change from a wiring layer to another wiring layer generally used hole connected, not through the pin pad device to achieve, because the plug in the device may be damaged when the relationship between this connection, there is current in every passage of 1A, at least two through-hole, through hole diameter is greater than the principle of 0.5mm, 0.8mm generally processed ensure reliability.Cooling devices, in some small power supply, the circuit board traces can be and cooling, characterized by the alignment as generous as possible to increase the cooling area is not coated solder, conditions can even be placed over holes, enhanced thermal conductivity .Today to talk about the aluminum plate in the switching power supply application and multilayer printed circuit in the switching power supply applications.Aluminum plate by its own structure, has the following characteristics: very good thermal conductivity, single Mianfu copper, the device can only be placed in tied copper surface, can not open electrical connection hole so as not to placejumper in accordance with a single panel.Aluminum plate is generally placed patch device, switch, the output rectifier heat conduction through the substrate to go out, very low thermal resistance, high reliability can be achieved. Transformer with planar chip structure, but also through substrate cooling, the temperature is lower than the conventional, the same size transformer with a large aluminum plate structure available output power. Aluminum plate jumper bridge approach can be used. Aluminum plate power are generally composed by the two PCB, another one to place the control circuit board, through the physical connection between the two boards is integrated.As the excellent thermal conductivity of aluminum plate, in a small amount of manual welding more difficult, solder cooling too fast and prone to problems of a simple and practical way of existing, an ironing ordinary iron (preferably temperature regulation function), over and iron for the last, fixed, and temperature to 150 ℃and above the aluminum plate on the iron, heating time, and then affix the components according to conventional methods and welding, soldering iron temperature is appropriate to the device easy to , is too high when the device may be damaged, or even copper strip aluminum plate, the temperature is too low welding effect is not good, to be flexible.Recent years, with the multi-layer circuit board applications in switching power supply circuit, printed circuit transformer makes it possible, due to multilayer, smaller spacing also can take advantage of Bianya Qi window section, the main circuit board can be re- Add 1-2 formed by the multilayer printed coil to use the window, the purpose of reducing circuit current density, due to adopt printed coil, reducing manual intervention, transformers consistency, surface structure, low leakage inductance, coupling good . Open-type magnetic core, good heat dissipation. Because of its many advantages, is conducive to mass production, it is widely used. But the research and development of large initial investment, not suitable for small-scale health.Switching power supply is divided into, two forms of isolation and non-isolated, isolated here mainly to talk about switching power supply topologies form below, non-specified,are to isolate the power. Isolated power supply in accordance with the structure of different forms, can be divided into two categories: a forward and flyback. Flyback transformer primary side means that when the Vice-edge conduction cut-off, transformer storage. Close of the primary, secondary side conduction, the energy released to the load of work status, general conventional flyback power multiplex, twin-tube is not common. Forward refers to the primary conduction in transformer secondary side while the corresponding output voltage is induced into the load, the direct transfer of energy through the transformer. According to specifications can be divided into conventional forward, including the single-transistor forward, Double Forward. Half-bridge, bridge circuits are all forward circuit.Forward and flyback circuits have their own characteristics in the process of circuit design to achieve optimal cost-effective, can be applied flexibly. Usually in the low-power flyback can be adopted. Slightly larger forward circuit can use a single tube, medium-power can use Double Forward circuit or half-bridge circuit, low-voltage push-pull circuit, and the half-bridge work in the same state. High power output, generally used bridge circuit, low voltage can be applied push-pull circuit.Flyback power supply because of its simple structure, and to cut the size of a similar size and transformer inductance, the power supply in the medium has been widely applied. Presentation referred to in some flyback power supply can do dozens of watts, output power exceeding 100 watts would be no advantage to them difficult. Under normal circumstances, I think so, but it can not be generalized, PI's TOP chips can do 300 watts, an article describes the flyback power supply can be on the KW, but not seen in kind. Power output and the output voltage level.Flyback power transformer leakage inductance is a critical parameter, because the power needs of the flyback transformer stored energy, to make full use of transformer core, the general must be open in the magnetic circuit air gap, the aim is to change the core hysteresis back line of the slope, so that transformers can withstand the impact of a large pulse current, which is not core into saturation non-linear state, the magnetic circuit in the highreluctance air gap in the state, generated in the magnetic flux leakage is much larger than completely closed magnetic circuit .Transformer coupling between the first pole is the key factor determining the leakage inductance, the coil to be very close as far as possible the first time, the sandwich can be used around the law, but this would increase the distributed capacitance transformer. Use core as core with a long window, can reduce the leakage inductance, such as the use of EE, EF, EER, PQ-based EI type magnetic core effective than good.The duty cycle of flyback power supplies, in principle, the maximum duty cycle of flyback power supply should be less than 0.5, otherwise not easy loop compensation may be unstable, but there are some exceptions, such as the U.S. PI has introduced the TOP series chip can work under the conditions of duty cycle is greater than 0.5.Duty cycle by the transformer turns ratio to determine former deputy side, I am an anti-shock view is, first determine the reflected voltage (output voltage reflected through the transformer coupling the primary voltage value), reflecting a certain voltage range of voltage increase is duty cycle increases, lower power loss. Reduce the reflected voltage duty cycle decreases, increases power loss. Of course, this is a prerequisite, when the duty cycle increases, it means that the output diode conduction time, in order to maintain output stability, more time will be to ensure that the output capacitor discharge current, the output capacitor will be under even greater high-frequency ripple current erosion, while increasing its heat, which in many circumstances is not allowed.Duty cycle increases, change the transformer turns ratio, transformer leakage inductance will increase, its overall performance change, when the leakage inductance energy large enough, can switch to fully offset the large account space to bring low-loss, no further increase when the meaning of duty, because the leakage inductance may even be too high against the peak voltage breakdown switch. Leakage inductance as large, may make the output ripple, and other electromagnetic indicators deteriorated. When the duty hours, the high RMS current through the switch, transformer primary current rms and lowered the converter efficiency, butcan improve the working conditions of the output capacitor to reduce fever. How to determine the transformer reflected voltage (duty cycle)Some netizens said switching power supply feedback loop parameter settings, work status analysis. Since high school mathematics is rather poor, "Automatic Control Theory," almost on the make-up, and for the door is still feeling fear, and now can not write a complete closed-loop system transfer function, zero for the system, the concept of feeling pole vague, see Bode plot is only about to see is a divergence or convergence, so the feedback compensation can not nonsense, but there are a number of recommendations. If you have some mathematical skills, and then have some time to learn then the University of textbooks, "Principles of Automatic Control" digest look carefully to find out, combined with practical switching power supply circuit, according to the work of state for analysis. Will be harvested, the Forum has a message, "coach feedback loop to study the design, debugging," in which CMG good answer, I think we can reference.Then today, on the duty cycle of flyback power supply (I am concerned about the reflected voltage, consistent with the duty cycle), the duty cycle with the voltage selection switch is related to some early flyback switching power supply using a low pressure tube, such as 600V or 650V AC 220V input power as a switch, perhaps when the production process, high pressure tubes, easy to manufacture, or low-pressure pipes are more reasonable conduction losses and switching characteristics, as this line reflected voltage can not be too high, otherwise the work order to switch the security context of loss of power absorbing circuit is quite impressive.Reflected voltage 600V tube proved not more than 100V, 650V tube reflected voltage not greater than 120V, the leakage inductance voltage spike when the tubes are clamped at 50V 50V working margin. Now that the MOS raise the level of manufacturing process control, flyback power supplies are generally used 700V or 750V or 800-900V the switch. Like this circuit, overvoltage capability against a number of switching transformer reflected voltage can be done a bit higher, the maximum reflected voltage in the 150V is appropriate, to obtain better overallperformance.TOP PI's recommendation for the 135V chipset with transient voltage suppression diode clamp. But his evaluation board generally reflected voltage to be lower than the value at around 110V. Both types have their advantages and disadvantages: Category: shortcomings against over-voltage, low duty cycle is small, a large pulse current transformer primary. Advantages: small transformer leakage inductance, electromagnetic radiation and low ripple index higher switch loss, the conversion efficiency is not necessarily lower than the second.The second category: a large number of shortcomings of power loss, a large number of transformer leakage inductance, the ripple worse. Advantages: Some strong against over-voltage, large duty cycle, lower transformer losses and efficiency higher.Reflected voltage flyback power supply and a determining factorReflected voltage flyback power supply with a parameter related to that is the output voltage, output voltage, the lower the larger the transformer turns ratio, the greater the transformer leakage inductance, switch to withstand higher voltage breakdown switch is possible to absorb power consumption is higher, has the potential to permanently absorb the circuit power device failure (particularly with transient voltage suppression diode circuits). In the design of low-voltage low-power flyback power output optimization process must be handled with care, its approach has several:1, using a large core of a power level lower leakage inductance, which can improve the low-voltage flyback power conversion efficiency, reduce losses, reduce output ripple and improve multi-output power of the cross regulation in general is common in household appliances with a switch power, such as CD-ROM drive, DVB set-top boxes.2, if the conditions were not increased core, can reduce the reflected voltage, reducing the duty cycle. Reduce the reflected voltage can reduce the leakage inductance but may reduce the power conversion efficiency, which is a contradiction between the two, must have an alternative process to find a suitable point, replace the transformer during the experiment can detect the transformer original side of the anti-peak voltage, peak voltage to minimize theanti-pulse width, and magnitude of the work safety margin increase converter. Generally reflected voltage 110V when appropriate.3, enhance the coupling, reducing losses, the introduction of new technologies, and the routing process, transformers to meet the security specifications will between the primary and secondary side to insulation measures, such as pad tape, plus side air insulation tape. These will affect the performance of transformer leakage inductance, the reality can be used in production around the primary winding secondary wrapping method. Or sub-system with a triple insulated wire wound to remove the insulation between the initial level, can enhance the coupling, even use wide copper winding.The article refers to low voltage output is less than or equal to 5V output, as this type of small power supply, my experience is that the power output of more than 20W output can use a forward, get the best value for money, of course, this is not the right decision , and personal habits, relationship between the application environment, the next time to talk about the flyback power supply with a magnetic core, magnetic circuit air gap opening some understanding, I hope you receive adequate guidance.Flyback power transformer core magnetization state at work in one way, it needs to open the air gap magnetic circuit, similar to the pulsating direct current sensor. Part of the magnetic coupling through the air gap. Why I understand the principle of open air gap as follows: As the power ferrite also has a similar rectangle of the operating characteristics (hysteresis loop), operating characteristics curve in the Y-axis magnetic induction (B), now the general production process saturation point in 400mT above, the general value in the design of this value should be more appropriate in the 200-300mT, X-axis magnetic field strength (H) the value of current intensity is proportional to the magnetization. Open magnetic circuit air gap equal to the magnetic hysteresis loop to the X axis tilt, in the same magnetic induction intensity, can withstand a greater magnetizing current, equivalent to core store more energy, this energy cut-off switch When spilled into the load through the transformer secondary circuit, flyback power core to open the air gap is twofold. One is to transfer more energy, and the second toprevent the core into saturation.Flyback Power Transformer magnetization state in one way, not only to pass through the magnetic coupling energy, is also responsible for input and output isolation voltage transform multiple roles. Therefore, the treatment gap need to be very careful, the air gap leakage inductance can become too large, increase the hysteresis loss, iron loss, copper loss increases, affecting the power of the whole performance. Air gap is too small has the potential to transformer core saturation, resulting in damage to powerThe so-called flyback power supply is continuous and discontinuous mode transformer working conditions, working in full load condition in the power transformer complete transfer, or incomplete transmission mode. General design of the working environment, conventional flyback power supply should work in continuous mode, this switch, circuit loss are relatively small, and can reduce the stress of work input and output capacitors, but that there are some exceptions.Requires in particular that: As the characteristics of the flyback power supply is also more suitable for design into a high-voltage power supply, and high-voltage power transformers generally work in discontinuous mode, I understand the need for as high voltage power supply output voltage of the rectifier diodes. Because of the manufacturing process characteristics, high-tension diode, reverse recovery time is long, low speed, the current continuous state, the diode has a positive bias in the recovery, reverse recovery energy loss is very large, is not conducive to converter performance increase, ranging from reduced conversion efficiency, rectifiers, severe fever, weight is even burnt rectifier. As in the intermittent mode, the diode is reverse biased under zero bias, loss can be reduced to a relatively low level. Therefore, high voltage power supply work in discontinuous mode, and the frequency can not be too high.Another type of flyback power supply work in the critical state, the general type of power supply work in FM, or FM-width-modulated dual-mode, a number of low-cost self-excitation power (RCC) is often used this form in order to ensure stable output transformer As the operating frequency, output current or input voltage change, close tothe fully loaded transformer is always maintained at between continuous and intermittent, this power is only suitable for small power output, otherwise the handling characteristics of electromagnetic compatibility will be a headacheFlyback switching power supply transformer should work in continuous mode, it required relatively large winding inductance, of course, is to some extent continuous, excessive pursuit of absolute continuity is not realistic, may need a great core, very much coil turns, accompanied by a large leakage inductance and distributed capacitance, worth the trouble. So how does this parameter to determine, through repeated practice, and analysis of peer design, I think, in the nominal voltage input, the output reached 50% and 60% transformer from intermittent, continuous state of transition to more appropriate. Or at the highest input voltage state, the full output, the transformer can transition to the continuous state on it.。

开关稳压电源外文文献及翻译(英文)

DC Switching Power Supply Protection TechnologyPosted:2006-2-26 10:57:00 visit:665 chinese Version Related NewsAbstract: The DC switching power supply protection system is proposed to protect the system design principles and machine protection measures, analysis of switching power supply in the range of protected characteristics and design method, introduced several practical protection of circuit.Keywords: switching power supply protection circuit system design1 IntroductionDC switching regulator used in the price of more expensive high-power switching devices, the control circuit is also more complex, In addition, the load switching regulators are generally used a large number of highly integrated devices installed electronic systems. Transistors and integrated device tolerance of electricity, less heat shocks. Thus switching regulator should take into consideration the protection of voltage regulators and load their own safety. Many different types of protection circuits introduced here polarity protection, program protection, over-current protection, over-voltage protection, under voltage protection and thermal protection circuits. Several protection methods are usually chosen to be combined to form a comprehensive protection system.2 Polarity ProtectionDC switching regulator's input are generally not regulated DC power supply. Due to operational errors or unforeseen circumstances will be the wrong polarity, switching power supply will be damaged. Polarity protection purposes, is to make the switching regulator only when the correct polarity is not regulated to DC power supply when connected to work. The use of a single wizard-pass device can achieve the power supply polarity protection. As the diode D to flow through the switching regulator's input total current, so this circuit applied in a low-power switching regulators on the more appropriate. Power in the larger occasion, put the polarity protection circuit as a program to protect a link, eliminating the need for high power required for polarity protection diodes, power consumption will be reduced. For convenient operation, easy to identify the polarity right or wrong。

开关电源外文文献.doc

开关电源外文文献DC Switching Power Supply Protection TechnologyAbstract : The DC switching power supply protection system, protection system design principles and machine protection measures, an analysis of switching power supply in the range of protected characteristics and its design methodology,introduced a number of practical protection circuit.Keywords : switching power supply protection circuit system design1、IntroductionDC switching regulator used in the price of more expensive high-power switching devices, the control circuit is also more complex, In addition, the load switching regulators are generally used a large number of highly integrated electronic systems installed devices. Transistors and integrated device tolerance electricity, less heat shocks. Switching Regulators therefore should take into account the protection of voltage regulators and load their own safety. Many different types of circuit protection, polarity protection, introduced here, the program protection, over-current protection, over-voltage protection, under-voltage protection and over-temperature protection circuit. Usually chosen to be some combination of protection, constitutes a complete protection system.2、polarity protectionDC switching regulator input are generally not regulated DC power supply. Operating errors or accidents as a result of the situation will take its wrong polarity, switching power supply will be damaged. Polarity protection purposes,is to make the switching regulator only when the correct polarity is not connected to DC power supply regulator to work at. Since the diode D to flow through switching regulator input total current, this circuit applied in a low-power switching regulator more suitable. Power in the larger occasion, whilethe polarity protection circuit as a procedure to protect a link, save the power required for polarity protection diodes, power consumption will be reduced. Inorder to easy to operate, make it easier to identify the correct polarity or not, collect the next light.3、procedures to protectSwitching power supply circuit is rather complicated, basically can be divided into low-power and high-power part of the control part of the switch. Switch is a high-power transistors, for the protection of the transistor switch is turned on or off power safety, we must first modulator, amplifier and other low-power control circuit. To this end, the boot to ensure the correct procedures. Switching Regulators generally take the input of a small inductor, the input filter capacitor. Moment in the boot, filter capacitor will flow a lot of surge current,the surge current can be several times more than the normal input current. Sucha large surge current may contact the general power switch or relay contact melting, and the input fuse fuse. In addition, the capacitor surge current will damage to shorten the life span of premature damage. To this end, the boot should be access to a current limiting resistor, through the current limiting resistor to capacitor charging. In order not to make the current limiting resistor excessive power consumption, thus affecting the normal switching regulator, andthe transient process in the boot after a short period then automatically relays itto DC power supply directly to the switching regulator power supply. This circuit switching regulator called a "soft start" circuit.Switching regulator control circuit of the logic components required or op-amp auxiliary power supply. To this end, the auxiliary power supply must bein the switch circuit. This control circuit can be used to ensure the boot. Normal boot process is: to identify the polarity of input power, voltage protection procedures → boot → auxiliary power supply circuit and through current limiting resistor R of the switching regulator input capacitor C → charge modulation switching regulator circuit, -circuit→shortcurrent limiting resistor stability switching regulator.In the switching regulator, the machines just because the output capacitance, and charge to the rated output voltage value of the need for a certain period of time. During this time, sampling the output amplifier with low input voltage sampling, closed-loop regulation characteristics of the system will force the switching of the transistor conduction time lengthened, so that switchingtransistor during this period will tend to continuous conduction, and easily damaged. To this end, the requirements of this paragraph in the boot time, the switch to switch the output modulation circuit transistor base drive signal of the pulse width modulation, can guarantee the switching transistor by the cut-off switches are becoming more and more normal state, therefore the protection of the setting up ofa boot to tie in with the soft start.4、over-current protectionWhen the load short-circuit, overload control circuit failure or unforeseen circumstances, such as would cause the flow of switching voltage regulator transistor current is too large, so that increased power tubes, fever, if there is no over-current protection device, high power switching transistor may be damaged. Therefore, the switching regulator in the over-current protection is commonly used. The most economical way is to use simple fuse. As a result of the heat capacity of small transistors, general fuse protection in general can not play a role in the rapid fuse common fuse. This method has the advantage of the protection of vulnerable, but it needs to switch transistor in accordance with specific security requirements of the work area to select the fuse specifications. This disadvantage is over-current protection measures brought about by the inconvenience of frequent replacement of fuses.Linear voltage regulator commonly used in the protection and current limitingto protect the cut-off in the switching regulator can be applied. However, according to the characteristics of switching regulators, the protection circuit can not directly control the output transistor switches, and overcurrent protection must be converted to pulse output commands to control the modulator to protect the transistor switch. In order to achieve over-current protection are generally required sampling resistor in series in the circuit, thiswill affect the efficiency of power supply, so more for low-power switching regulator of occasions. In the high-power switching power supply, by taking into account the power consumption should be avoided as far as possible access to the sampling resistor. Therefore, there will usually be converted to over-current protection, and under-voltage protection.5、over-voltage protectionSwitching regulator's input over-voltage protection, including over-voltageprotection and output over-voltage protection. Switching regulator is not used inDC power supply voltage regulator and rectifier, such as battery voltage, if toohigh, so switching regulator is not working properly, or even damage to internaldevices, therefore, it is necessary to use the input over-voltage protection circuit.In the circuit, when the input DC power supply voltage higher than thevoltage regulator diode breakdown voltage value, the breakdown voltageregulator tube, a current flowing through resistor R, so that V turn-on transistor,relay, normally closed contact off open, cut off the input. Voltage regulatorvoltage regulator which controls the value of Vz = ESrmax-UBE. The polarity ofinput power with the input protection circuit can be combined with over-voltageprotection, polarity protection constitute a differential circuit and overvoltage protection.Output over-voltage protection switching power supply is essential. Inparticular, for the 5V output of the switching regulator, it is a lot of load on ahigh level of integration of the logic device. If at work, switching regulatorsudden damage to the switch transistor, the output potential may be increasedimmediately to the importation of non-regulated DC power supply voltage value,causing great loss instantaneous. Commonly used method is short-circuitprotection thyristor. The simplest over-voltage protection circuit. When theoutput voltage is too high, the regulator tube breakdown triggered thyristorturn-on, the output short-circuit, resulting in over-current through the fuse orcircuit protective device to cut off the input to protect the load. This circuit is equivalent to the response time of the o pening time of thyristor is about 5 ~ 10 μ s. The disadvantage is that its action is fixed voltage, temperature coefficient, andaction points of instability. In addition, there is a voltage regulator control parameters of the discrete, model over-voltage start-up the same but hasdifferent values, difficult to debug.6、under-voltage protectionOutput voltage below the value to reflect the input DC power supply, switching regulator output load internal or unusual occurrence. Input DC power supplyvoltage drops below the specified value would result in switching regulator outputvoltage drops, the input current increases, not only endanger the switchingtransistor, but also endanger the input power. Therefore, in order to set up due tovoltage protection.When no voltage regulator input normal, ZD breakdown voltage regulator tube, transistors V conduction, the relay action, contact pull-in, power-switching regulator.When the input below the minimum allowable voltage value, the regulator tube ZDbarrier, V cut-off, contact Kai-hop, switching regulator can not work. Internalswitching regulator, as the control switch transistor circuit disorders or failure willdecrease the output voltage; load short-circuit output voltage will also decline.Especially in the reversed-phase step-up or step-up switching regulator DC voltageof the protection due to over-current protection with closely related and thereforemore important. Implementation of Switching Regulators in the termination of theoutput voltage comparators.Normally, there is no comparator output, once the voltage drops below the allowable value in the comparator on the flip, drive alarm circuit; also fedback to the switching regulator control circuit, so that switching transistor cut-off or cut off the input power.7、over-temperature protectionSwitching regulator and the high level of integration of light-weight small volume, with its unit volume greatly increased the power density, power supplycomponents to its work within the requirements of the ambient temperature isalso a corresponding increase. Otherwise, the circuit performance willdeteriorate, premature component failure. Therefore, in high-power switchingregulator should be set up over-temperature protection.Relays used to detect the temperature inside the power supply temperature, when the internally generated power supply overheating, the temperature of therelay on the action, so that whole circuit in a warning alarm, and the realizationof the power supply over-temperature protection. Temperature relay can beplaced in the vicinity of the switching transistor, the general high-power tube shell to allow the maximum temperature is 75 ℃ , adjust the temperature settingto 60 ℃ . When the shell after the temperature exceeds the allowable value to cut off electrical relay on the switch protection. Semiconductor switching device thermal "hot thyristor," in the over-temperature protection, played an important role. It canbe used as directed circuit temperature. Under the controlof p-hot-gate thyristor (TT102) characteristics, by RT value to determine the temperature of the device turn-on, RT greater the temperature the lower the turn-on.When placed near the power switching transistor or power device, it will be able to play the role of temperature instructions. When the power control the temperature of the shell or the internal device temperature exceeds the allowed value, the heat conduction thyristor on, so that LED warning light. If the optocoupler with, would enable the whole circuit alarm action to protect the switching regulator. It can also be used as a power transistor as the over-temperature protection, crystal switch the base current by n-type gate control thyristor TT201 thermal bypass, cut-off switch to cut off the collector current to prevent overheating.8、ConclusionDiscussed above in the switching regulator of a variety of conservation, and introduces a number of specific ways to achieve. Of a given switching power supply is concerned, but also protection from the whole to consider the following points:1)the switching regulator used in the switching transistor in the DC security restrictions on the work of regional work. The transistor switches selected by the manual available transistors get DC safe working area. According to the maximum collector current to determine the input value of over-current protection. However, the instantaneous maximum value should be converted to the average current. At rated output current and output voltage conditions, the switch of the dynamic load line does not exceed a safe working area DC maximum input voltage, input over-voltage protection is the voltage value.2)the switching regulator output limit given by the technical indicators within. Work within the required temperature range, the switching regulator'soutput voltage, the lower limit of the output is off, due to the voltage value of voltage protection. Over-current protection can be based on the maximum output current to determine. False alarm in order not to protect the value of a certain margin to remain appropriate.3)from the above two methods to determine the protection after the power supply device in accordance with the needs of measures to determine the alarm. Measures the general alarm sound and light alarm two police. Voice of the police applied to more complex machines, power supply parts and do not stand out in a place, it can give staff an effective warning of failure; optical Police instructions can be eye-catching and fault alarm and pointed out that the fault location and type. Protection measures should be protected as to determine the location. In the high-power, multi-channel power supply, always paying, DC circuit breakers, relays, etc. high-sensitivity auto-protection measures, to cut off the input power supply to stop working the system from damage. Through the logic control circuit to make the appropriate program cut-off switch transistor is sensitive it is convenient and economic. This eliminated large, long response time, the price of your high-power relay or circuit breaker.4)the power of putting in the protection circuit will be affected after the reliability of the system, for which want to protect the reliability of the circuit itself is higher in order to improve the reliability of the entire power system, thereby increasing its own power supply MTBF. This requires the protection ofstrict logic, the circuit is simple, at least components, In addition to the protection circuit should also be considered a failure of maintenance of their difficulty and their power to protect the damage.Therefore, we must be comprehensive and systematic consideration of a variety of switching power supply protection measures to ensure the normal operation of switching power supplies and high-efficiency and high reliability.。

英文文献科技类原文及翻译 (电子电气自动化通信…) 8

Switching Power Supply目录1 Switching Power Supply (1)Linear versus Switching Power Supplies (1)Basic Converters (2)1.2.1Forward-Mode Converter Fundamentals (2)1.2.3 Flyback or Boost-mode Converter Fundamentals (4)1.3 Topologies (5)1 开关电源 (7)1.1 线性电源和开关电源之比拟 (7)根本转换器 (8)1.2.1 前向模式转换器根底 (8)12.2 增压模式转换器根底 (8)1.3 拓扑结构 (9)2 Operational Amplifiers (10)2 放大器 (14)1 Switching Power SupplyEvery new electronic product , except those that battery powered, requires converting off-line 115V ac or 230V ac power to some dc voltage for powering the electronics. Efficient conversion of electrical power is becoming a primary concern to companies and to society as a whole.Switching power supplies offer not only higher efficiencies but also offer greater flexibility to the designer. Recent advances in semiconductor, magnetic and passive technologies make the switching power supply an ever more popular choice in the power conversion arena today.1.1 Linear versus Switching Power SuppliesHistorically, the linear regulator was the primary method of creating a regulated output voltage. It operates by reducing a higher input voltage down to the lower output voltage by linearly controlling the conductivity of a series pass power device in response to changes in its load. This results in a large voltage being placed across the pass unit with the load current flowing through it.This headroom loss ()V I⨯ causes the linear regulator to only be 30 todrop load50 percent efficient. That means that for each watt delivered to the load , at least a watt has to be dissipated in heat. The cost of the heatsink actually makes the linear regulator uneconomical above 10watts for small applications. Below that point, however, they are cost effective in step-down applications.The switching regulator operates the power devices in the full-on and cutoff states. This then results in either large currents being passed through the power devices with a low“on〞voltage or no current flowing with high voltage across the device. This results in a much lower power being dissipated within the supply.The average switching power-supply exhibits efficiencies of between 70 to 90 percent, regardless of the input voltage.Higher levers of integration have driven the cost of switching power supplies downward which makes in an attractive choice for output powers greater than 10 watts or where multiple outputs are desired.1.2 Basic ConvertersForward-Mode Converter FundamentalsThe most elementary forward-mode converter is the Buck or Step-down Converter which can be seen in Figure 3.1.Its operation can be seen as having two distinct time periods which occur when the series power switch is on and off. When the power switch is on ,the inputvoltage is connected to the input of the inductor .The output of switch of inductor is the output voltage, and the rectifier is back-biased. During this period, since there is a constant voltage source connected across the inductor, the inductor current begins to linearly ramp upward which is described by:()()in out on L on V V t i L -⨯=During the “on 〞 period , energy is being stored within the core material of the inductor in the form of flux. There is sufficient energy stored to carry the requirements of the load during the next off period.The next period is the “off 〞 period of the power switch .When the power switch turns off, the input voltage of the inductor flies below ground and is clamped at one diode drop below ground by the catch diode. Current now begins to flow through the catch diode thus maintaining the load current loop. This remove the stored energy from the inductor, The inductor. The inductor current during this time is:()()out D offL off V V t i L -⨯=This period ends when the power switch is once again turned on.Regulation is accomplished by varying the on-to-off duty cycle of the power switch. The relationship which approximately describes its operation is:out in V V ≈∂⨯Where ∂ is the duty cycle (()/on on off t t t ∂=+).The buck converter is capable of kilowatts of output power, but suffers from one serious shortcoming which would occur if the power switch were to fail short-circuited, the input power source is connected directly to the load circuitry with usually produces catastrophic results. To avoid this situation, a crowbar is placed across the output. A crowbar is a latching SCR which is fired when the output is sensed as entering an overvoltage condition. The buckconverter should only be used for board-level regulation.Flyback or Boost-mode Converter FundamentalsThe most elementary flyback-mode converter is the boost or Step-up Converter. Its schematic can be seen in Figure3.2.Its operation can also be broken into two distinct periods where the power switch is on or off. When power switch turns on, the input voltage source is placed directly across the inductor. This causes the current to begin linearly ramping upwards from zero and is described by:()in on L on V t i L ⨯=Once again, energy is being stored during each cycle times the frequency of operation must b higher than the power demands of the load or,20.5sto pkop out P L I f P =⨯⨯>The power switch then turns off and the inductor voltage flies back abovethe input voltage and is clamped and is clamed by the rectifier at the output voltage .The current then begins to linearly ramp downward until the until the energy within the core is completely depleted. Its waveform which is shown in Figure 3.3 is determined by:()()out in offL off V V t i L -⨯=The boost converter should also be only used for board-level regulation.1.3 TopologiesA topology is the arrangement of the power devices and their magnetic elements. Each topology has its own merits within certain applications. Some of the factors which determine the suitability of a particular topology to a certain application are:1) Is the topology electrically isolated from the input to the output or not.2) How much of the input voltage is placed across the inductor or transformer.3) What is the peakcurrent flowing through the power semiconductors.4) Are multiple outputs required.5) How much voltage appears across the power semiconductors.The first choice that faces the designer is whether to have input to output transformer isolation. Non-isolated switching power supplies are typically used for board-level regulation where a dielectric barrier is provided elsewhere within the system. Non-isolated topologies should also be used where the possibility of a failure does not connect the input power source to the fragile load circuitry. Transformer isolation should be used in all other situations. Associated with that is the need for multiple output voltages. Transformers provide an easy method for adding additional output voltage to the switching power supply. The companies building their own power systems are leaning toward transformer isolation in as many power supplies as possible since it prevents a domino effect during failure conditions.1 开关电源除了那些用电池做电源的电子产品外，每个新型电子产品都需要将115V或者230V 的交流电源转换为直流电源，为电路供电。

智能开关电源中英文对照外文翻译文献

中英文对照外文翻译(文档含英文原文和中文翻译)英文：Intelligent switch power supplyWith the rapid development of electronic technology, application field of electronic system is more and more extensive, electronic equipment, there are more and more people work with electronic equipment, life is increasingly close relationship. Any electronic equipment are inseparable from reliable power supply for power requirements, they more and more is also high. Electronic equipment miniaturized and low cost in the power of light and thin, small and efficient for development direction. The traditional transistors series adjustment manostat is continuous control linear manostat. This traditional manostat technology more mature, and there has been a large number of integrated linear manostat module, has the stable performance is good, output ripple voltage small, reliable operation, etc. But usually need are bulky and heavy industrial frequency transformer and bulk and weight are big filter.In the 1950s, NASA to miniaturization, light weight as the goal, for a rocket carrying the switch power development. In almost half a century of developmentprocess, switch power because of its small volume, light weight, high efficiency, wide range, voltage advantages in electric, control, computer, and many other areas of electronic equipment has been widely used. In the 1980s, a computer is made up of all of switch power supply, the first complete computer power generation. Throughout the 1990s, switching power supply in electronics, electrical equipment, home appliances areas to be widely, switch power technology into the rapid development. In addition, large scale integrated circuit technology, and the rapid development of switch power supply with a qualitative leap, raised high frequency power products of, miniaturization, modular tide.Power switch tube, PWM controller and high-frequency transformer is an indispensable part of the switch power supply. The traditional switch power supply is normally made by using high frequency power switch tube division and the pins, such as using PWM integrated controller UC3842 + MOSFET is domestic small power switch power supply, the design method of a more popularity.Since the 1970s, emerged in many function complete integrated control circuit, switch power supply circuit increasingly simplified, working frequency enhances unceasingly, improving efficiency, and for power miniaturization provides the broad prospect. Three end off-line pulse width modulation monolithic integrated circuit TOP (Three switch Line) will Terminal Off with power switch MOSFET PWM controller one package together, has become the mainstream of switch power IC development. Adopt TOP switch IC design switch power, can make the circuit simplified, volume further narrowing, cost also is decreased obviouslyMonolithic switching power supply has the monolithic integrated, the minimalist peripheral circuit, best performance index, no work frequency transformer can constitute a significant advantage switching power supply, etc. American PI (with) company in Power in the mid 1990s first launched the new high frequency switching Power supply chip, known as the "top switch Power", with low cost, simple circuit, higher efficiency. The first generation of products launched in 1994 represented TOP100/200 series, the second generation product is the TOP Switch - debuted in1997 Ⅱ. The above products once appeared showed strong vitality and he greatly simplifies thedesign of 150W following switching power supply and the development of new products for the new job, also, high efficiency and low cost switch power supply promotion and popularization created good condition, which can be widely used in instrumentation, notebook computers, mobile phones, TV, VCD and DVD, perturbation VCR, mobile phone battery chargers, power amplifier and other fields, and form various miniaturization, density, on price can compete with the linear manostat AC/DC power transformation module.Switching power supply to integrated direction of future development will be the main trend, power density will more and more big, to process requirements will increasingly high. In semiconductor devices and magnetic materials, no new breakthrough technology progress before major might find it hard to achieve, technology innovation will focus on how to improve the efficiency and focus on reducing weight. Therefore, craft level will be in the position of power supply manufacturing higher in. In addition, the application of digital control IC is the future direction of the development of a switch power. This trust in DSP for speed and anti-interference technology unceasing enhancement. As for advanced control method, now the individual feels haven't seen practicability of the method appears particularly strong,perhaps with the popularity of digital control, and there are some new control theory into switching power supply.（1）The technology: with high frequency switching frequencies increase, switch converter volume also decrease, power density has also been boosted, dynamic response improved. Small power DC - DC converter switch frequency will rise to MHz. But as the switch frequency unceasing enhancement, switch components and passive components loss increases, high-frequency parasitic parameters and high-frequency EMI and so on the new issues will also be caused.（2）Soft switching technologies: in order to improve the efficiency of non-linearity of various soft switch, commutation technical application and hygiene,representative of soft switch technology is passive and active soft switch technology, mainly including zero voltage switch/zero current switch (ZVS/ZCS) resonance, quasi resonant, zero voltage/zero current pulse width modulation technology (ZVS/ZCS - PWM) and zero voltage transition/zero current transition pulse width modulation (PWM) ZVT/ZCT - technical, etc. By means of soft switch technology can effectively reduce switch loss and switch stress, help converter transformation efficiency （3）Power factor correction technology (IC simplifies PFC). At present mainly divided into IC simplifies PFC technology passive and active IC simplifies PFC technology using IC simplifies PFC technology two kinds big, IC simplifies PFC technology can improve AC - DC change device input power factor, reduce the harmonic pollution of power grid.（4）Modular technology. Modular technology can meet the needs of the distributed power system, enhance the system reliability.（5）Low output voltage technology. With the continuous development of semiconductor manufacturing technology, microprocessor and portable electronic devices work more and more low, this requires future DC - DC converter can provide low output voltage to adapt microprocessor and power supply requirement of portable electronic devicesPeople in switching power supply technical fields are edge developing related power electronics device, the side of frequency conversion technology, development of switch between mutual promotion push switch power supply with more than two year growth toward light, digital small, thin, low noise and high reliability, anti-interference direction. Switching powersupply can be divided into the AC/DC and DC/DC two kinds big, also have AC/AC DC/AC as inverter DC/DC converter is now realize modular, and design technology and production process at home and abroad, are mature and standardization, and has approved by users, but the AC/DC modular, because of its own characteristics in the process of making modular, meet more complex technology and craft manufacture problems. The following two types of switch power supply respectively on the structure and properties of this.Switching power supply is the development direction of high frequency, high reliability, low consumption, low noise, anti-jamming and modular. Because light switch power, small, thin key techniques are changed, so high overseas each big switch power supply manufacturer are devoted to the development of new high intelligent synchronous rectifier, especially the improvement of secondary devices of the device, and power loss of Zn ferrite (Mn) material? By increasing scientific and technological innovation, to enhance in high frequency and larger magnetic flux density (Bs) can get high magnetic under the miniaturization of, and capacitor is a key technology. SMT technology application makes switching power supply has made considerable progress, both sides in the circuitboard to ensure that decorate components of switch power supply light, small, thin. The high frequency switching power supply of the traditional PWM must innovate switch technology, to realize the ZCS ZVS, soft switch technology has become the mainstream of switch power supply technical, and greatly improve the efficiency of switch power. For high reliability index, America's switch power producers, reduce by lowering operating current measures such as junction temperature of the device, in order to reduce stress the reliability of products made greatly increased.Modularity is of the general development of switch power supply trend can be modular power component distributed power system, can be designed to N + 1 redundant system, and realize the capacity expansion parallel. According to switch power running large noise this one defect, if separate the pursuit of high frequency noise will increase its with the partial resonance, and transform circuit technology, high frequency can be realized in theory and can reduce the noise, but part of the practical application of resonant conversion technology still have a technical problem, so in this area still need to carry out a lot of work, in order to make the technology to practional utilization.Power electronic technology unceasing innovation, switch power supply industry has broad prospects for development. To speed up the development of switch power industry in China, we must walk speed of technological innovation road, combinationwith Chinese characteristics in the joint development path, for I the high-speed development of national economy to make the contribution. The basic principle and component functionAccording to the control principle of switch power to classification, we have the following 3 kinds of work mode:1) pulse width adjustment type, abbreviation Modulation Pulse Width pulse width Modulation (PWM) type, abbreviation for. Its main characteristic is fixed switching frequency, pulse width to adjust by changing voltage 390v, realize the purpose. Its core is the pulse width modulator. Switch cycle for designing filter circuit fixed provided convenience. However, its shortcomings is influenced by the power switch conduction time limit minimum of output voltage cannot be wide range regulation; In addition, the output will take dummy loads commonly (also called pre load), in order to prevent the drag elevated when output voltage. At present, most of the integrated switch power adopt PWM way.2) pulse frequency Modulation mode pulse frequency Modulation (, referred to Pulse Frequency Modulation, abbreviation for PFM) type. Its characteristic is will pulse width fixed by changing switch frequency to adjust voltage 390v, realize the purpose. Its core is the pulse frequency modulator. Circuit design to use fixed pulse-width generator to replace the pulse width omdulatros and use sawtooth wave generator voltage？Frequency converter (for example VCO changes frequency VCO). It on voltage stability principle is: when the output voltage Uo rises, the output signal controller pulse width unchanged and cycle longer, make Uo 390v decreases, and reduction. PFM type of switch power supply output voltage range is very wide, output terminal don't meet dummy loads. PWM way and way of PFM respectively modulating waveform is shown in figure 1 (a), (b) shows, tp says pulse width (namely power switch tube conduction time tON), T represent cycle. It can be easy to see the difference between the two. But they have something in common: (1) all use time ratio control (TRC) on voltage stability principle, whether change tp, finally adjustment or T is pulse 390v. Although adopted in different ways, but control goals, is all rivers run into the sea. (2) when load by light weight, or input voltagerespectively, from high changed by increasing the pulse width, higher frequency method to make the output voltage remained stable.3) mix modulation mode, it is to point to the pulse width and switching frequency is not fixed, each other can change, it belongs to the way the PWM and PFM blend mode. It contains a pulsewidthomdulatros and pulse frequency modulator. Because and T all can adjust alone, so occupies emptiescompared to adjust the most wide range, suitable for making the output voltage for laboratories that use a wide range of can adjust switching power supply. Above 3 work collectively referred to as "Time Ratio Control" (as a Control, from TRC) way. As noted, pulse width omdulatros either as a independent IC use (for example UC3842 type pulse width omdulatros), can also be integrated in DC/DC converter (for example LM2576 type switching voltage regulators integrated circuit), still can integration in AC/DC converter (for example TOP250 type monolithic integrated circuit switching power supply. Among them, the switching voltage regulators belong to DC/DC power converter, switching power supply general for AC/DC power converter.The typical structure of switch power as figure1shows, its working principle is: the first utility into power rectifier and filtering into high voltage dc and then through the switch circuit and high-frequency switch to high frequency low pressure pulse transformer, and then after rectification and filter circuits, finally output low voltage dc power. Meanwhile in the output parts have a circuit feedback to control circuit, through the control PWM occupies emptiescompared to achieve output voltage stability.The input filter RectifierfilterHighfrequencytransformerInputrectifierfilterControlcircuitAuxiliarypowerProtectioncircuitdetectionAC The outputdcFigure 1 typical structure of switch power supplySwitching power supply by these four components:1) the main circuit: exchange network input, from the main circuit to dc output. Mainly includes input filter, rectifier and filtering, inverter, and output rectifier and filtering.(1) input filter: its effect is the power grid existing clutter filtering, also hinder the machine produces clutter feedback to public power grid.(2) rectifier and filter: the power grid ac power directly for a smooth dc rectifier, for the next level transformation.(3) inverter: will the dc after rectifying a high-frequency ac, this is the core of high frequency switching power supply, the higher the frequency, the volume, weight and the ratio of power output and smaller.(4) Out put rectifier and filter: according to load needs, providing stable and reliable dc power supply. 2) control circuit: on the one hand, from the output by sampling with set standards to compare, and then to control inverter, changing its frequency or pulse width, achieve output stability, on the other hand, according to data provided by the test circuit, the protection circuit differential, provide control circuit to the machine to various protection measures. Including the output feedback circuit and sampling circuit, pulse width modulator. 3) the detection and protection circuit: detection circuit had current detection, over-voltage detection, owe voltage detection, overheat detection, etc.; Protection circuit can be divided over current protection, over-voltage protection, owe voltage protection, the ground-clamp protection, overheating protection, automatic restart, soft start, slow startup, etc. Various types. 4) Other circuit: if the sawtooth wave generator, offset circuit, optical coupler, etc.智能开关电源中文：随着电子技术的高速发展，电子系统的应用领域越来越广泛，电子设备的种类也越来越多，电子设备与人们的工作、生活的关系日益密切。

开关电源中英文对照外文翻译文献

开关电源中英文对照外文翻译文献(文档含英文原文和中文翻译)Modeling, Simulation, and Reduction of Conducted Electromagnetic Interference Due to a PWM Buck Type Switching Power Supply IA. FarhadiAbstract:Undesired generation of radiated or conducted energy in electrical systems is called Electromagnetic Interference (EMI). High speed switching frequency in power electronics converters especially in switching power supplies improves efficiency but leads to EMI. Different kind of conducted interference, EMI regulations and conducted EMI measurement are introduced in this paper. Compliancy with national or international regulation is called Electromagnetic Compatibility (EMC). Power electronic systems producers must regard EMC. Modeling and simulation is the first step of EMC evaluation. EMI simulation results due to a PWM Buck type switching power supply are presented in this paper. To improve EMC, some techniques are introduced and their effectiveness proved by simulation.Index Terms:Conducted, EMC, EMI, LISN, Switching SupplyI. INTRODUCTIONFAST semiconductors make it possible to have high speed and high frequency switching in power electronics []1. High speed switching causes weight and volume reduction of equipment, but some unwanted effects such as radio frequency interference appeared []2. Compliance with electromagnetic compatibility (EMC) regulations is necessary for producers to present their products to the markets. It is important to take EMC aspects already in design phase []3. Modeling and simulation is the most effective tool to analyze EMC consideration before developing the products. A lot of the previous studies concerned the low frequency analysis of power electronics components []4[]5. Different types of power electronics converters are capable to be considered as source of EMI. They could propagate the EMI in both radiated and conducted forms. Line Impedance Stabilization Network (LISN) is required for measurement and calculation of conducted interference level []6. Interference spectrum at the output of LISN is introduced as the EMC evaluation criterion []7[]8. National or international regulations are the references for the evaluation of equipment in point of view of EMC []7[]8.II. SOURCE, PATH AND VICTIM OF EMIUndesired voltage or current is called interference and their cause is called interference source. In this paper a high-speed switching power supply is the source of interference.Interference propagated by radiation in area around of an interference source or by conduction through common cabling or wiring connections. In this study conducted emission is considered only. Equipment such as computers, receivers, amplifiers, industrial controllers, etc that are exposed to interference corruption are called victims. The common connections of elements, source lines and cabling provide paths for conducted noise or interference. Electromagnetic conducted interference has two components as differential mode and common mode []9.A. Differential mode conducted interferenceThis mode is related to the noise that is imposed between different lines of a test circuit by a noise source. Related current path is shown in Fig. 1 []9. The interference source, path impedances, differential mode current and load impedance are also shown in Fig. 1.B. Common mode conducted interferenceCommon mode noise or interference could appear and impose between the lines, cables or connections and common ground. Any leakage current between load and common ground could be modeled by interference voltage source.Fig. 2 demonstrates the common mode interference source, common mode currents Iandcm1 and the related current paths[]9. The power electronics converters perform as noise source Icm2between lines of the supply network. In this study differential mode of conducted interference is particularly important and discussion will be continued considering this mode only.III. ELECTROMAGNETIC COMPATIBILITY REGULATIONS Application of electrical equipment especially static power electronic converters in different equipment is increasing more and more. As mentioned before, power electronics converters are considered as an important source of electromagnetic interference and have corrupting effects on the electric networks []2. High level of pollution resulting from various disturbances reduces the quality of power in electric networks. On the other side some residential, commercial and especially medical consumers are so sensitive to power system disturbances including voltage and frequency variations. The best solution to reduce corruption and improve power quality is complying national or international EMC regulations. CISPR, IEC, FCC and VDE are among the most famous organizations from Europe, USA and Germany who are responsible for determining and publishing the most important EMC regulations. IEC and VDE requirement and limitations on conducted emission are shown in Fig. 3 and Fig. 4 []7[]9.For different groups of consumers different classes of regulations could be complied. Class A for common consumers and class B with more hard limitations for special consumers are separated in Fig. 3 and Fig. 4. Frequency range of limitation is different for IEC and VDE that are 150 kHz up to 30 MHz and 10 kHz up to 30 MHz respectively. Compliance of regulations is evaluated by comparison of measured or calculated conducted interference level in the mentioned frequency range with the stated requirements in regulations. In united European communitycompliance of regulation is mandatory and products must have certified label to show covering of requirements []8.IV. ELECTROMAGNETIC CONDUCTED INTERFERENCE MEASUREMENTA. Line Impedance Stabilization Network (LISN)1-Providing a low impedance path to transfer power from source to power electronics converter and load.2-Providing a low impedance path from interference source, here power electronics converter, to measurement port.Variation of LISN impedance versus frequency with the mentioned topology is presented inFig. 7. LISN has stabilized impedance in the range of conducted EMI measurement []7.Variation of level of signal at the output of LISN versus frequency is the spectrum of interference. The electromagnetic compatibility of a system can be evaluated by comparison of its interference spectrum with the standard limitations. The level of signal at the output of LISN in frequency range 10 kHz up to 30 MHz or 150 kHz up to 30 MHz is criterion of compatibility and should be under the standard limitations. In practical situations, the LISN output is connected to a spectrum analyzer and interference measurement is carried out. But for modeling and simulation purposes, the LISN output spectrum is calculated using appropriate software.For a simple fixed frequency PWM controller that is applied to a Buck DC/DC converter, it is) changes slow with respect to the switching frequency, the possible to assume the error voltage (vepulse width and hence the duty cycle can be approximated by (1). Vp is the saw tooth waveform amplitude.A. PWM waveform spectral analysisThe normalized pulse train m (t) of Fig. 8 represents PWM switch current waveform. The nth pulse of PWM waveform consists of a fixed component D/fs , in which D is the steady state duty cycle, and a variable component dn/f sthat represents the variation of duty cycle due to variation of source, reference and load.As the PWM switch current waveform contains information concerning EMI due to powersupply, it is required to do the spectrum analysis of this waveform in the frequency range of EMI studies. It is assumed that error voltage varies around V e with amplitude of V e1as is shown in (2).fm represents the frequency of error voltage variation due to the variations of source, reference and load. The interception of the error voltage variation curve and the saw tooth waveform with switching frequency, leads to (3) for the computation of duty cycle coefficients []10.Maximum variation of pulse width around its steady state value of D is limited to D1. In each period of Tm=1/fm , there will be r=fs/fm pulses with duty cycles of dn. Equation (4) presents the Fourier series coefficients Cn of the PWM waveform m (t). Which have the frequency spectrum of Fig.9.B-Equivalent noise circuit and EMI spectral analysisTo attain the equivalent circuit of Fig.6 the voltage source Vs is replaced by short circuit and) as it has shown in Fig. 10. converter is replaced by PWM waveform switch current (IexThe transfer function is defined as the ratio of the LISN output voltage to the EMI current source as in (5).The coefficients di, ni (i = 1, 2, … , 4) c orrespond to the parameters of the equivalent circuit. Rc and Lc are respectively the effective series resistance (ESR) and inductance (ESL) of the filter capacitor Cf that model the non-ideality of this element. The LISN and filter parameters are as follows: CN = 100 nF, r = 5 Ω, l = 50 uH, RN =50 Ω, LN=250 uH, Lf = 0, Cf =0, Rc= 0, Lc= 0, fs =25 kHzThe EMI spectrum is derived by multiplication of the transfer function and the source noise spectrum. Simulation results are shown in Fig. 11.VI. PARAMETERS AFFECTION ON EMIA. Duty CycleThe pulse width in PWM waveform varies around a steady state D=0.5. The output noise spectrum was simulated with values of D=0.25 and 0.75 that are shown in Fig. 12 and Fig. 13. Even harmonics are increased and odd ones are decreased that is desired in point of view of EMC.On the other hand the noise energy is distributed over a wider range of frequency and the level of EMI decreased []11.B. Amplitude of duty cycle variationThe maximum pulse width variation is determined by D1. The EMI spectrum was simulatedwith D1=0.05. Simulations are repeated with D1=0.01 and 0.25 and the results are shown in Fig.14and Fig.15.Increasing of D1 leads to frequency modulation of the EMI signal and reduction in level ofconducted EMI. Zooming of Fig. 15 around 7thcomponent of switching frequency in Fig. 16shows the frequency modulation clearly.C. Error voltage frequencyThe main factor in the variation of duty cycle is the variation of source voltage. The fm=100 Hz ripple in source voltage is the inevitable consequence of the usage of rectifiers. The simulation is repeated in the frequency of fm=5000 Hz. It is shown in Fig. 17 that at a higher frequency for fm the noise spectrum expands in frequency domain and causes smaller level of conducted EMI. On the other hand it is desired to inject a high frequency signal to the reference voltage intentionally.D. Simultaneous effect of parametersSimulation results of simultaneous application of D=0.75, D1=0.25 and fm=5000 Hz that leadto expansion of EMI spectrum over a wider frequencies and considerable reduction in EMI level is shown in Fig. 18.VII. CONCLUSIONAppearance of Electromagnetic Interference due to the fast switching semiconductor devices performance in power electronics converters is introduced in this paper. Radiated and conducted interference are two types of Electromagnetic Interference where conducted type is studied in this paper. Compatibility regulations and conducted interference measurement were explained. LISN as an important part of measuring process besides its topology, parameters and impedance were described. EMI spectrum due to a PWM Buck type DC/DC converter was considered and simulated. It is necessary to present mechanisms to reduce the level of Electromagnetic interference. It shown that EMI due to a PWM Buck type switching power supply could be reduced by controlling parameters such as duty cycle, duty cycle variation and reference voltage frequency.VIII. REFRENCES[1] Mohan, Undeland, and Robbins, “Power Electronics Converters, Applications and Design” 3rdedition, John Wiley & Sons, 2003.[2] P. Moy, “EMC Related Issues for Power Electronics”, IEEE, Automotive Power Electronics, 1989, 28-29 Aug. 1989 pp. 46 – 53.[3] M. J. Nave, “Prediction of Conducted Interference in Switched Mode Power Supplies”, Session 3B, IEEE International Symp. on EMC, 1986.[4] Henderson, R. D. and Rose, P. J., “Harmonics and their Effects on Power Quality and Transfor mers”, IEEE Trans. On Ind. App., 1994, pp. 528-532.[5] I. Kasikci, “A New Method for Power Factor Correction and Harmonic Elimination in Power System”, Proceedings of IEEE Ninth International Conference on Harmonics and Quality of Power, Volume 3, pp. 810 – 815, Oct. 2000.[6] M. J. Nave, “Line Impedance Stabilization Networks: Theory and Applications”, RFI/EMI Corner, April 1985, pp. 54-56.[7] T. Williams, “EMC for Product Designers” 3rd edition 2001 Newnes.[8] B. Keisier, “Principles of Electromagnetic Compatibility”, 3rd edition ARTECH HOUSE 1987.[9] J. C. Fluke, “Controlling Conducted Emission by Design”, Vanhostrand Reinhold 1991.[10] M. Daniel,”DC/DC Switching Regulator Analysis”, McGrawhill 1988[11] M. J. Nave,” The Effect of Duty Cycle on SMPS Common Mode Emission: theory and experiment”, IEEE National Symposium on Electromagnetic Compatibility, Page(s): 211-216, 23-25 May 1989.基于压降型PWM开关电源的建模、仿真和减少传导性电磁干扰IIA. Farhadi摘要：电子设备之中杂乱的辐射或者能量叫做电磁干扰(EMI)。

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