外文翻译--高频开关电源电路原理-精品
高频开关电源详细介绍
高频开关电源详细介绍高频开关电源（High-Frequency Switching Power Supply）是一种广泛应用于电子设备中的电源系统。
相比传统的线性电源，高频开关电源具有高效率、小体积、轻重量和稳定的电压输出等优点。
本文将详细介绍高频开关电源的工作原理、主要组成部分以及应用领域。
高频开关电源的工作原理如下：当输入电压接通时，由交流电源经过整流和滤波后，经过开关器件进行高频开关，然后经过变压器变换电压，之后经过滤波、稳压和反馈电路调节后输出稳定的直流电压。
整个过程中，开关器件在开关状态下，能以更高的频率进行开关操作，以提高转换效率和减小体积。
高频开关电源的主要组成部分包括输入端、整流滤波器、开关器件、变压器、输出电路以及保护电路等。
输入端主要接收交流电源，并通过整流滤波器将其转换为直流电压。
开关器件是高频开关电源的核心部分，负责快速开关操作，常见的开关器件包括MOSFET（金属氧化物半导体场效应管）和IGBT（绝缘栅双极型晶体管）等。
变压器则用于将输入电压变换为合适的电压，并通过输出电路将其稳定输出。
保护电路主要用于确保电源在工作过程中的安全性和稳定性，包括过载保护、短路保护和过温保护等。
高频开关电源具有较高的转换效率，一般可以达到85%以上，而传统的线性电源则只有60%左右的效率。
这是因为在高频开关电源中，开关器件可以迅速地通过开关操作来控制电源的输出，并通过反馈控制电路来实现稳定的电压输出，大大提高了能量转换的效率。
由于高频开关电源具有高效率的特点，可以减少电源损耗，降低能源消耗，因此在现代电子设备中得到了广泛应用。
高频开关电源的应用领域十分广泛，例如计算机、通讯设备、工业自动化设备以及医疗仪器等。
在计算机中，高频开关电源被广泛应用于各种电子设备，如主机、显示器和服务器等。
通讯设备方面，高频开关电源可以为手机、路由器和网络交换机等提供稳定的电源。
在工业自动化设备中，高频开关电源可以为机器人、PLC（可编程逻辑控制器）以及传感器等提供经济高效的电源解决方案。
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。
开关电源工作原理如何理解及其电路图详细解析
开关电源工作原理如何理解及其电路图详细解析开关模式电源(Switch Mode Power Supply，简称SMPS)，又称交换式电源、开关变换器，是一种高频化电能转换装置，是电源供应器的一种。
其功能是将一个位准的电压，透过不同形式的架构转换为用户端所需求的电压或电流。
开关电源的输入多半是交流电源(例如市电)或是直流电源，而输出多半是需要直流电源的设备，例如个人电脑，而开关电源就进行两者之间电压及电流的转换。
开关模式电源(Switch Mode Power Supply，简称SMPS)，又称交换式电源、开关变换器，是一种高频化电能转换装置，是电源供应器的一种。
其功能是将一个位准的电压，透过不同形式的架构转换为用户端所需求的电压或电流。
开关电源的输入多半是交流电源(例如市电)或是直流电源，而输出多半是需要直流电源的设备，例如个人电脑，而开关电源就进行两者之间电压及电流的转换。
开关电源不同于线性电源，开关电源利用的切换晶体管多半是在全开模式(饱和区)及全闭模式(截止区)之间切换，这两个模式都有低耗散的特点，切换之间的转换会有较高的耗散，但时间很短，因此比较节省能源，产生废热较少。
理想上，开关电源本身是不会消耗电能的。
电压稳压是透过调整晶体管导通及断路的时间来达到。
相反的，线性电源在产生输出电压的过程中，晶体管工作在放大区，本身也会消耗电能。
开关电源的高转换效率是其一大优点，而且因为开关电源工作频率高，可以使用小尺寸、轻重量的变压器，因此开关电源也会比线性电源的尺寸要小，重量也会比较轻。
若电源的高效率、体积及重量是考虑重点时，开关电源比线性电源要好。
不过开关电源比较复杂，内部晶体管会频繁切换，若切换电流尚加以处理，可能会产生噪声及电磁干扰影响其他设备，而且若开关电源没有特别设计，其电源功率因数可能不高。
主要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，安防监控，LED灯带，电脑机箱，数码产品和仪器类等领域。
电气类外文翻译---- 开关电源的发展
外文资料译文THE DEVELOPMENT OF SWITCHING POWER 1955 United States Royer (GH.Roger) invented the transistor single push-pull oscillation transformer DC-DC converter, frequency conversion control circuit to achieve the beginning of 1957, the United States Charles race (Jen Sen) invented the self-excited push-pull double transformer, in 1964 U.S. scientists have proposed to abolish the frequency transformer switching power supply series idea, which is the power to decline in volume and weight were a fundamental way. To 1969 because of pressure to improve high-power silicon transistors, diode reverse recovery time shortened components to improve, and finally made a 25 kHz switching power supply. At present, switching power supply to small, light weight and high efficiency characteristics are widely used in a variety of computer-driven devices, communications equipment, etc. Almost all the electronic equipment is the rapid development of today's electronic information industry, an indispensable Power Source. Currently on the market the use of switching power bipolar transistors made of 100kHz, 500kHz with a power MOSFET made, Although practical, its frequency needs to be improved. To improve the switching frequency, it is necessary to reduce switching losses, and to reduce switching losses, it needs high-speed switching components. However, the switching speed of the increase will be distributed by the circuit inductance and capacitance, or diode stored charge of the generated surge or noise. This will not only affect nearby electronic equipment, will greatly reduce the reliability of power supply itself. Which, with the switch to prevent Kai - closed by the voltage surge occurs, can use RC or LC buffer, while the stored charge from the diode can be used due to current surges such as core made of amorphous magnetic buffer .However, for more than 1MHz frequency, resonant circuit to be used to make the switch voltage or current through the switch was a sine wave, this can reduce the switching losses, but also to control the occurrence of surge. This switch is called resonant switch. Current switching power supply of this very active, because this approach does not require substantial increase in switching speed can be reduced theoretically to zero switching losses and noise are small, is expected to be of a high-frequency switching power supply main ways. At present, many countries are working on a few trillion Hz, the practical application of converter.Switching power supply direction of development is high-frequency, high reliability, low power, low noise, interference and modular. Oxygen material increase scientific and technological innovation to enhance the high frequency and higher magnetic flux density (Bs) obtained a high magnetic properties, while the small capacitor is a key technology. SMT technology allows switching power supply hasmade considerable progress, both sides of the circuit board layout components to ensure that the switching power supply of light, small, thin. High frequency switching power supply will be bound to the traditional PWM switching technology innovation, realization of ZVS, ZCS soft switching power supply switching technology has become the mainstream technology, and a substantial increase in the switching power supply efficiency.For high reliability, the U.S. manufacturer of switching power supply by reducing operating current to reduce junction temperature and other measures to reduce the stress of the device makes the improved reliability of products.Modular switching power supply is the general trend of development can be composed of modular power distributed power systems can be designed to N +1 redundant power systems, and parallel way to achieve the capacity expansion. Switching power supply noise for the big run this shortcoming, if the individual pursuit of its high-frequency noise will also increase with, while using some of the resonant converter circuit technology, in theory, but also can reduce the high frequency of the noise, but some the practical application of resonant conversion technology, there are still technical problems, it still required much work in this area in order to make the technology to practical use.With the power electronics technology development, switching power supply industry has a bright future. Switching power supply industry in China should speed up the pace of development, we must take the technical innovation, out of the Industry and Academia with Chinese characteristics development road, as the rapid development of our national economy to contribute.开关电源的发展1955年美国罗耶（GH.Roger)发明的自激振荡推挽晶体管单变压器直流变换器，是实现高频转换控制电路的开端，1957年美国查赛（Jen Sen)发明了自激式推挽双变压器，1964年美国科学家们提出取消工频变压器的串联开关电源的设想，这对电源向体积和重量的下降获得了一条根本的途径。
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)。
中英翻译--开关电源-精品
Switching Power SupplySwitching power supply is a voltage conversion circuit, the main work is the step-up and step-down, are widely used in modern electronic products. Always work because the switching transistor in the "on" and "off" state, so called switching power supply. Switching power supply in real terms is an oscillator circuit, the conversion of electrical energy not only used in power circuit, the circuit in other applications are also common, such as LCD backlight circuits, such as fluorescent lamps. Switch the source compared with the transformer high efficiency, good stability, small size and other advantages, disadvantages is the relatively small power, and high-frequency interference on the circuit, circuit complexity, such as easy maintenance.Talking about switching power supply before you familiar with the feedback oscillator circuit transformer, can produce a regular pulse current or voltage of the circuit is called oscillation circuit, transformer feedback oscillator circuit is able to meet these conditions the circuit; it in the basic amplifier circuit with a feedback loop composed of C2, L1 election to form a parallel resonant frequency circuit, the instantaneous power in the circuit turn-VT, this time in the C2, L1, composed of parallel resonant circuits have a very rich harmonic, when the plus parallel resonance frequency and the natural frequency of the same circuit, the circuit to enter a state of oscillation, and VT through L3 feedback to further enlarge the base, and ultimately the formation of a regular pulse current or voltage output to the load RL. Switching power supply is around the transformer and the feedback oscillator circuit design, but the basis of the original increase in the number of protection and control circuits, analysis of our oscillation circuit can be used to analyze the method of switching power supply.Switching Power Supply vibration by way of sub-swing can be divided into self-excited and it excited the two, since there is no need for plus-excited self-oscillation signal source, since the excitation can see it as a feedback oscillator circuit transformer, and it is excited is totally dependent on the outside to maintain the oscillation, in the practical application of self-excitation of a comprehensive range of applications. According to the structure of incentives signal classification; can be divided into pulse-width-modulated pulse amplitude modulation and two pulse-width-modulated signal to control the width, that is, frequency, pulse amplitude modulation control signal of the magnitude of the role of the two the same so that oscillation frequency is maintained at within a certain range, to the effect of voltage stability. Winding transformer can be divided into three types in general, a group involved in the primary winding of the oscillation, a group is to maintain the oscillation of the feedback winding, there is a group of the load windings. Household appliances used in switching power supply,after the AC to 220V bridge rectifier, converted into about 300V DC, filter into the transformer is added after the switch to high-frequency oscillations of the collector, feedback winding back to the base tomaintain the oscillation circuit, load sensor windings of the electrical signal, by rectification, filtering, the DC voltage regulator has been to provide power to the load. Winding in the provision of electric power load, but also take up the capacity of voltage stability, the theory is then a circuit voltage output voltage sampling devices to monitor the output voltage changes, timely feedback to adjust the oscillation frequency oscillator circuit to achieve the voltage stability The purpose of the circuit in order to avoid interference, the feedback voltage to the oscillator circuit will be isolated optocoupler. Most switches have a standby power circuit, switching power supply in standby mode still oscillating, but the frequency of normal working hours than lower.Some switching power supply are complex, numerous components, many protection and control circuit, in the absence of technical support, maintenance is a headache with the matter. I face this kind of situation is, first of all, I will find the switch and its participation in the external oscillation circuit, it separated from the circuit to see if it met the conditions for oscillation, such as detection bias and whether it is normal, whether positive feedback failure, as well as its own switches, switching power supply has very large protection, after exclusion of the prosecution and load control and protection circuit.the control circuit while output from the sample, with the set standards, then controlled inverter, change its frequency or pulse width output achieve stability, on the other hand, according to test data provided by the circuit by circuit protection identification, Control circuit for the unit for various protection measures.SMPS developments and trends in the United States in 1955 Roje (GH.Roger) invention of the self-excited oscillation push redeem transistor single transformer DC converters, high-frequency conversion is the beginning of control circuit, 1957 United States investigation tournament (Jen Sen) since the invention of the push-pull double Flyback transformers, 1964 American scientists proposes to abolish the frequency transformer series switching power supply scenario, This power to the right size and weight of the decline was a fundamental way. To the 1969 high-power silicon transistor because the pressure increase diode reverse recovery time shortened, and other components improve, and finally turned into a 25 kHz switching power supply.Currently, switching power supply to small, Light volume and the characteristics of high efficiency has been widely used in electronic computer-driven variety of terminal equipment, Communications equipment almost all electronic equipment, the electronic information industry indispensable to the rapid development of a power mode. Currently the market for sale in the switching power supply using bipolar transistors made of 100kHz. use made of 500kHz MOS power, though practical, but its frequency to be further enhanced. To improve the switching frequency, it is necessary to reduce the switching loss, and to reduce the switching loss, you need to have high-speed switching devices. However, the switching speed, will be affected by the circuit inductance and capacitance diode or stored charge arising from the impact of the surge ornoise. This will not only affect the surrounding electronic equipment, but also greatly reduce the reliability of the power supply itself. Among them, with the switch to prevent Kai-closed by the voltage surge, it is R-C or L-C Composite bumpers, and the storage charge by the diode current surge caused by the use made of amorphous cores such as magnetic bumper. However, the high frequency of 1 MHz and above, using resonant circuit, Switch to enable the voltage or current through the switch was a sine, which could reduce the switching loss, This can also control the surge occurred. Switches such as resonant mode switching. Currently such SMPS of very active, because this means no significant increase switching speed can theoretically put switching loss fall to zero. and the noise is small, is expected to become high-frequency switching power supply of one of the main ways. At present, many countries in the world are working on several trillion Hz converter practical research.开关电源开关电源是一种电压转换电路，主要的工作内容是升压和降压，广泛应用于现代电子产品。
高频开关电路原理_翻译
High-frequency switching powersupply circuit of high frequency switching power supply from the following components:first a main circuit from the exchange network input, DC output of the entire process, including : an import filter : its role is to network the clutter filtration, but also hindered the plane of the clutter feedback to the public grid. 2, rectifier and filter : direct AC power rectifier for smoother DC, for under a transformation. 3, the inverter : Rectifier the high frequency alternating current into direct current, high-frequency switching power supply is the core component of the higher frequency, size, weight and output ratio smaller. 4, and the rectifier output filter : Under load the need to provide stable and reliable DC power supply.second, the control circuit while output from the sample, with the set standards, then controlled inverter, change its frequency or pulse width output achieve stability, on the other hand, according to test data provided by the circuit by circuit protection identification, Control circuit for the unit for various protection measures.Third, in addition to providing detection circuit protection circuit is running various parameters, but also provide information display instruments.Fourth, the auxiliary power supply circuit for the single power supply to the different requirements.Switching regulator control principleSwitching Control Switching Regulators K principle to a certain time interval repeatedly connected and disconnected, connected to the switch K, Input voltage E and K through switching circuit filter to load RL, the entire switch connected, Power E to provide energy load; When K disconnect switch, the input power is interrupted E. energy delivery. This shows that the importation of power to provide energy load is intermittent, for the load can be provided for the energy, Switching power supply must be a set of storage devices, the switches will be connected to a part of the energy stored in the switch disconnected. Load to the release. Map from the inductance L, capacitance diode D and C2 components of the circuit, it is such a function. Inductor L for energy storage in switch disconnected, stored in the inductor L of energy release through diodes D to load, so that load is continuous and stable energy, diode D enable continuous load current, known as the continued flow diode. AB in the average voltage EAB can be given by : EAB=TON/T*E where TON connected to the switch each time, T-off switch for the cycle (that is, access time TON switch and turn-off time and TOFF''s). - We can see from the change switch connected to the work cycle time and the ratio of the voltage between the AB average change also, therefore, With the load and input supply voltage changes and automatically adjust TON T ratio, it will cause the output voltage V0 unchanged. Change the access time and cycle TON percentage change is the pulse duty cycle. This method, known as "time ratio control" (Time Ratio Control, for the initials TRC). TRC under control principle, there are three ways : 1. Pulse width modulation (Pulse Width Modulation, acronym for PWM) switching constant cycle by changing the pulse width to change the duty cycle approaches. 2, pulse frequency modulation (Pulse Frequency Modulation, acronym for the PFM) conduction pulse width constant by changing the switching frequency to change the duty cycle approaches. 3, mixed conduction modulation and pulse width switching frequency notfixed are, they change the way It is more than two hybrid models.SMPS developments and trends in the United States in 1955 Roje (GH.Roger) invention of the self-excited oscillation push redeem transistor single transformer DC converters, high-frequency conversion is the beginning of control circuit, 1957 United States investigation tournament (Jen Sen) since the invention of the push-pull double Flyback transformers, 1964 American scientists proposes to abolish the frequency transformer series switching power supply scenario, This power to the right size and weight of the decline was a fundamental way. To the 1969 high-power silicon transistor because the pressure increase diode reverse recovery time shortened, and other components improve, and finally turned into a 25 kHz switching power supply.Currently, switching power supply to small, Light volume and the characteristics of high efficiency has been widely used in electronic computer-driven variety of terminal equipment, Communications equipment almost all electronic equipment, the electronic information industry indispensable to the rapid development of a power mode. Currently the market for sale in the switching power supply using bipolar transistors made of 100kHz. use made of 500kHz MOS power, though practical, but its frequency to be further enhanced. To improve the switching frequency, it is necessary to reduce the switching loss, and to reduce the switching loss, you need to have high-speed switching devices. However, the switching speed, will be affected by the circuit inductance and capacitance diode or stored charge arising from the impact of the surge or noise. This will not only affect the surrounding electronic equipment, but also greatly reduce the reliability of the power supply itself. Among them, with the switch to prevent Kai-closed by the voltage surge, it is R-C or L-C Composite bumpers, and the storage charge by the diode current surge caused by the use made of amorphous cores such as magnetic bumper. However, the high frequency of 1 MHz and above, using resonant circuit, Switch to enable the voltage or current through the switch was a sine, which could reduce the switching loss, This can also control the surge occurred. Switches such as resonant mode switching. Currently such SMPS of very active, because this means no significant increase switching speed can theoretically put switching loss fall to zero. and the noise is small, is expected to become high-frequency switching power supply of one of the main ways. At present, many countries in the world are working on several trillion Hz converter practical research.高频开关电源的电路原理高频开关电源的电路由以下部分组成:一、主电路从交流电网输入，直流输出的全过程，包括:1、输入过滤器:它的作用是网络的杂波过滤,并且阻碍公共输电网的杂波反馈给平面。
电气外文文献及翻译--开关电源设计
外文文献：Switching Power Supply DesignSwitching 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.First, layout: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, and electrolytic 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 Figure (1) Figure 1 better than Yu Figure 2, Figure 2 Zai 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 thedesign 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 the pin 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. Shearpin 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 attention to the pad holes set to zero.3. 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 the solder 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 unexpectedfactors, 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 place jumper 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 thephysical 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, DoubleForward. 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 high reluctance 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 loopcompensation 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, but can 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 timeto 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 overall performance.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 strongagainst 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 the anti-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 thistype 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 to prevent 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 incontinuous 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 to the 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 headache Flyback 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.中文译文：开关电源设计开关电源状态，电源工作在高频率，高脉冲的模拟电路的一个比较特殊的一种。
外文翻译--高频开关电源介绍
The Introduction OfHigh Frequency Switching Power SupplyIntroduction:High frequency switching power supply (also called switch rectifier SMR) through the MOSFET or the high frequency IGBT, switch frequency control in 50-100 KHZ, within the scope of efficient and realize miniaturization. In recent years, switch rectifier power capacity expansion, the capacity of himself, from the volt 48V/、48V/20A to48V/200A、48V/400A。
High frequency switching power supply is traditional rectifier (silicon rectifier, silicon-controlled rectifier) upgrade alternative products. High frequency switching power supply with convenient use, small size, high efficiency, stable work, coating meticulous etc absolute superiority quickly dominate the market. Widely used in electroplating electrolysis surface treatment industry oxidation and get old and new customers.Product features:一．This product USES imported brand components and international advanced bridge in precision machining technology of inverter, and make the performance is stable, the quality is reliable.二．For high-frequency pulse waveforms output ripple coefficient, the 1%, can improve the number of plating and surface aestivation, refuse the gloss and got a dark corner of plating. And can reduce the loss, raw materials of plating industry of special requirements.三．SFG series high frequency switching power supply by air-filled type design, installation convenience. With remote control device, easy for operation. Can bring load switch machine, reduce the adjustment of the complex procedures.四. Small volume light weight the comprehensive use of anticorrosive craft,enhance the ability of anti-corrosion products, prolong the life.五. Energy saving, high working efficiency reached more than 90%, any more than a linear always voltage matching. Save the traditional rectifier regulator and the energy loss, in more than 35%, greatly reduce the cost, the reason of surface treatment industryHigh frequency switching power supply一．The main circuitFrom the input and output of dc exchange network, including:1．The whole the effect is input filter: there will be the clutter power filter, also hindered the feedback to produce clutter of public power.2．And rectification and filtering: ac power grid directly to a smooth dc rectification, in order to the next level.3．Inverter: after rectifying dc into high frequency alternating, this is the core part of switch power supply, the higher the frequency volume, and weight and output power than smaller.4．And output rectifier and filtering: according to provide reliable, load of the dc power supply.Second control circuit：On one hand, the sample from the output terminal with setting standards, and then compared to control the inverter, change the frequency or pulse width, achieve output stability, on the other hand, according to the test circuit, the information provided by differential protection circuit, control circuit of various protection measures.Third detection circuit：In addition to providing protection circuit is running in the various parameters but also provide various display meter data.Four, the auxiliary powerTo provide all the different requirements of a circuit switching voltage control principleSwitch to certain time interval K repeatedly through and disconnect the switch, the power input, K E through switch and filter circuits provide load RL, throughout theswitch power load during to provide energy, E, When the switch, input power disconnection K E will provide energy interrupted. Visible, to provide the energy input power load is intermittent, for the load can be provided for energy switching power supply, a storage device, must be in switch will be part of the energy stored in the switch to load, release. In the figure, the inductance and capacitance C2 and diode L circuit, is composed of D this function. Inductance used in storing energy, l., and stored in the switch of energy through the diode inductance L D, released to load get steady and continuous energy, because diode D make continuous load current, so called free-wheeling diode. In EAB average voltage between AB says: under the type used:EAB = TON/T * EFor every TON of time, the switch to switch the huge T works cycle (i.e. switch time TON TOFF cut-off time and sum).By type, changing switch time and work cycle, the ratio between the average voltage AB also changed, therefore, with the load and the input voltage changes automatically adjusted TON and the proportion of T he can make the output voltage V0 remain unchanged. Change through Time and work cycle TON of pulse that changing proportion of this method, SHCH as "Time Ratio Control" (from Time, abbreviation for TRC).According to the control principle TRC have three ways:A Pulse Width Modulation (Pulse Width Modulation, the abbreviation for PWM) Switch is constant, by changing the pulse width to change the way SHCH. Second, Pulse Frequency, Pulse Modulation (some Modulation abbreviated PFM) The constant change of the pulse width, through the working frequency switches to change the way SHCH.Third, mix modulationConduction pulse width and switch jobs are not fixed frequency, each other can change the way, and it is more than two ways of mixed.High frequency switching power supply [1] don't need to increase speed switches cantheoretically the switch loss to zero, and noise is smallThe development of switch powerSwitching power supply for has the advantages of small size, light weight, high efficiency, low calorific value and stable performance advantages and gradually replace traditional manufacturing technology of continuous work power, and widely used in electronic machine and equipment. In the 1980s, the full realization of computer, the switching power supply complete computer. In the 1990s, switch power supply in electronics, electrical equipment, and home appliance field has been widely applied; switch power technology into rapid development.Switching voltage stabilizer adopts power semiconductor as switch, through the control switch SHCH adjustment output voltage. In power transistors (GTR), for example, when a switch tube saturated conductivity, the collector and emitter on both ends of the pressure drop to zero, When the switch tube, the collector current deadline to zero. So the consumption, efficiency can be up to 70-95. While consumption also decrease. Radiator switching voltage stabilizer for grid voltage directly rectifier, filter, and then adjusted by adjusting voltage switch pipe, need not power transformer. In addition, switch frequency for dozens of KHZ, filter capacitor, inductor value. Therefore switching power supply is light weight, small size, etc.In addition, due to the low consumption, low temperature; improve the stability and reliability of the machine. And on the grid adaptive capability has increased, the average power serial Manos tat allows for 220 ± 10% fluctuate, but switching voltage stabilizer in voltage in a 110-260 volts range change, can obtain stable output voltage.The high frequency switching power supply is the development of technology innovation technology, high frequency of the benefit is that switching power supply device to miniaturization, and make an unprecedented power switch into a wide range of areas, especially in the high-tech fields of application, promote the high-tech products of miniaturization, light. Now on the market of switch power supply power tube with a bipolar transistor, switch frequency can reach several KHZ, The switch power MOSFET using frequency conversion of hundreds of KHZ. To improve theswitch frequency, must adopt high speed switching devices. For the power switch frequency than MHZ available resonant circuit this way of working is called resonant switching mode.It can greatly improve switch speed, theoretically switch loss to zero, the noise is small, and it is to improve the working frequency of switch power. By way of resonant switching converter has practical level MHZ. Pursuit of switch power supply technical development trend and can be summarized in the following four aspects.A miniaturization, thin, light, high frequency switching power supply of -- of volume, weight is mainly composed of storage devices (magnetic components and capacitance), so the miniaturization of switch power supply is essentially to minimize the volume of storage devices, In a certain range, the switch frequency, not only can effectively reduce capacitance and inductance and the size of the transformer, but also can restrain the interference, improve the dynamic performance of the system. Therefore, high frequency switching power is the main development direction.Second, high reliability - the use of switch power supply for a job than components ten times, thus increasing the reliability. From the Angle of life, capacitors, optical coupler and platoon devices such as life determines the communication power of life. So, from design, use less as far as possible, improve integration. Such not only solved the reliability of complex, the circuit, also increases protection function, simplify the circuit improve MTBF.Third, low noise - one of switch power supply noise is. Simply pursuit of high frequency and noise also is met subsequently increased. The partial resonant converting circuit technology, in principle on which can not only improve the frequency and can reduce the noise. So, as far as possible to reduce the noise influence of switch power supply is a development direction.Four, using computer aided design and control -- USES the latest technology design CDD CAA and transformation of topology and the best parameters, make the switch power structure and the best condition. Jane, in the circuit into microcomputers detection and control, monitoring system, can form multi-function real-time detection, record and automatic alarm and etc.The development of switch power supply is and semiconductor devices and the development of magnetic components. The high frequency, need corresponding high-speed semiconductorA high-frequency electromagnetic with excellent performance. Development power MOSFET, IGBT etc, develop new high-speed device with low frequency magnetic materials, improving the loss of magnetic components of the structure and the design method, enhances the filter capacitor dielectric constant and reduce its equivalent series resistor etc, to switch power miniaturization has produced a great impetus高频开关电源介绍简介高频开关电源(也称为开关型整流器SMR)通过MOSFET或IGBT的高频工作，开关频率一般控制在50-100kHzX围内，实现高效率和小型化。
中英文翻译
NC switching power supplyAbstract：This system based on 51 SCM control unit, used for LM2576-wild numerical control a switching power supply of fuzzy digital control technology, adjust load R1, R2 proportion to change occupies empties compared to make the output stability, and can be through the buttons, digital display to realize output voltage numerical control. In addition, the system to input pressure, flow, input output flow, switch tube overheat as well as the protection circuit, ensure that the system is stable and reliable.Key words:the numerical control，switching power supply，LM2576-wild，micro controller (一)The overall design of the systemSystem to monolithic integrated circuit AT89S52, LM2576-for the core part, and the wild through the monolithic integrated circuit to output voltage gather, comparison, operations, and the output voltage control, automatic regulation system structure diagram shown as shown in figure 1.220 V / 50 Hz ac voltage after rectifying circuit and DC/DC voltage chip LM2576 wild transformation for stable-5 ~ 12 V DC voltage output, the output voltage through sampling circuit by sampling, A/D conversion chip ADC0804 after converting to 52 after processing, control simulation electron switch to choose 4051 respectively the nine potentiometer R2, change R1 and R2 ratio values, which change LM2576-of the wild chip PWM pulse of empty, MOS tubes work than to switch state in, the input of 15 V DC voltage "chopped" for the and of the same frequency PWM waves pulse wave, pulse wave through the rectifier filter circuit output for 5 ~ 12 V DC voltage. Because of this the topic request have nine output stepping demand, so can tune in advance each voltage resistance, through the corresponding key choice output voltage, directly to the analog switch 4067 choose resistance, they can get to output voltage. At the same time, to detect the voltage, current value through the display LCD1062 real-time display. If working current is too big, the flow detection circuit will be sent to the testing results of single-chip microcomputer, SCM control relaythrough the ac branch realize over-current protection system in fault, after the operation is set by the reset button to may cause the system to resume normal work. （二）The block diagram of the whole system(三) Unit circuit function and the analysis of the operation1. Minimum AT89S52 SCM systemMinimum system including crystal oscillator circuit and reset switch and power supply parts. Figure 2 for the minimum AT89S52 SCM system.The wave rectifier circuit is made up of two half wave of rectifier circuit. Because in the next two, add on miens input voltage of the opposite polarity, therefore, to a dynamic balance, in every signal cycle, the C1 and C2 experience 2 times charger, discharge process, current will appear two current pulse with polarity. So in addition to the V o saw tooth wave on the wavy frequency, improve the ability of double filtering, thus reduce ripple voltage.The dc power by power supply, filtering, protection, such as voltage, four basic modules.(1)The power transformer USES a step-down transformer, the power grid voltage 220 V transform into need ac voltage. The ac voltageAfter rectifying, may obtain electronic equipment need dc voltage.(2) Use rectifier circuit bridge rectifier circuit single-phase, 50 Hz ac alternating current transformation for direction invariable but still has the pulse size straight Flow electricity. Its advantage is high voltage ripple voltage, small, the utilization rate of transformer high. This design by A bridge pile of bridge rectifier, RS808 do maximum current can reach 8 A, cooperate with the design of the large filter capacitance, so the power of the instantaneous large current power supply characteristics, low noise, good reaction speed, output ripple small.（3）Filter circuit using capacitance filter circuit, will the pulsation of the rectifier circuit output filter, get most of the components is smooth dc the electricity. This circuit adopts 4700 u F / 50 V large capacitance C3, C4 to make the output voltage more smooth, the power supply characteristics moment, suitable for take the perceptual load, such as motor start-up. C3, C4 every parallel connection a 0.1 u F / 63 V CBB capacitance, filter to high frequency interference, make input to integrated circuits L11, L12 of dc as far as possible the smooth and pure.（4）By LM317 output voltage circuit is power, LM337 output negative supply. LM317 and LM337 are used internal heat Load, contains over current protection, hot off and safety working area for perfect protection circuit, that power can save the fuse, and so easy loss device. Regulating circuit: to meet the needs of the differentapplication situation and the voltage is set to can be adjusted. The calculation of the output voltage V o = 1.25 x (1 + Rf/R), adjustable resistance in use precision can be resistor and guarantee the precise output voltage can be adjusted. If this article chooses for 5 k of Rf Ω, R for 270 Ω combination, can respectively on 1.25 V ~ 24 V 1.25 V ~ 24 V achieve continuous adjustable between.（5）Protection circuit for linear power supply heat, so the power larger add enough radiator. Due to the high performance integrated circuit, which can simplify the circuit structure, highlighting the important part in the power transformation. Through the commissioning and testing, good performance. The whole circuit The power not only can be used alone, also can be in other electronic equipment used in voltage or current stabilization source use.2. LM2576-voltage circuit wildWorking principle:Assume that the switch transistors, diodes are ideal components, inductance and capacitance is ideal components, the output voltage ripple voltage output voltage and the ratio of the small to allow oversight.According to the current cycle to begin in IL inductance is starting from scratch, can be divided into current continuous working mode and inductance inductive current is discontinuous work patterns. Due to the continuous work mode inductance current converter, have very good control characteristic; Inductive current is discontinuous work mode, put the electric, inductance and capacitance easy to produce the oscillation, thus affecting the output voltage ripple; And the same occupies empties compared, output voltage in discrete model under the mode of work than the big, high efficiency. To sum up, the most ideal situation is in critical condition, stabilizer which work so we use two kinds of methods:(1)The increase of the inductance inductive energy storage, increase, and extend the discharge of time(2)Improve the work and reduce the frequency switch timeMake transistor in current continuous state.3. The whole wave output rectifier circuit parameter analysisOutput filter by free-wheeling diode rectifier circuit, inductance and capacitance composition. Consider free-wheeling diode in tube by PMOS transistor conduction, when energy consumption, and work in the state, so we used the low power consumption, high current, high-speed Scotty diodes IN5817, the characteristics as follows:Maximum peak reverse voltage: 40 VThe biggest reverse RMS voltage: 28 VThe biggest dc voltage: 40 V blockThe biggest positive average rectifier current: 1 AThe biggest positive pressure drop: 0.6 V (1 A) BUCK converter principle by analysis shows that in order to make work in inductive current circuit continuous mode, and the ripple voltage2221()88o o o s s V V D V t t T T LC LC=-= So as far as possible, should be made great inductance we choose for 8 mH inductanceCapacitors mainly is the "absorb" ripple with a smooth, the role of the voltage waveform. Capacitance and inductance is equivalent to a low pass filtering filter, the cut-off frequency defined asfc=Considering thecapacitance equivalent series resistance losses, we choose the capacitance for 1000 uF.562c f Hz ==≈ ()(2~4)gs th V V =-- At this time the cut-off frequency of ab o ut 562 Hz ac, visible to dozens of kHz PWM waves have very good filtering effect.4. Input over-voltage protectionWhen the input voltage in the normal range, the input sampling voltage comparator, less than the benchmark voltage output low level; When the input pressure, input voltage is greater than the benchmark sampling comparison output voltage, high level, ARM produce external interruption, warning, blockade, make PMOS transistor tube PWM signal, in order to protect the circuit damage.5. Over-current protectionUsually with hall current sensor detection of current directly PMOS transistor, and then with setting the Id threshold value, compared with comparison to control the output of the driver signal shut off; Or by indirect method, the flow test voltage when the voltage drop the Vsd PMOS transistor, because the pressure drop contains short-circuit current information flow, when the Vsd increasing, and basically for linear relationship, when the Vsd and with setting the threshold value is used in the comparison, the comparator output control power circuit of the shutoff.数控开关稳压电源摘要:本系统基于51单片机为控制单元，采用LM2576-ADJ数控开关稳压电源中的模糊数字控制技术，调整负载R1,R2比例来改变占空比使输出稳定，并且可通过按键、数码显示实现输出电压数控。
开关电源外文翻译
Pulse Width Modulator (PWM) General-Purpose TimersPWMPulse width modulation (PWM) is a powerful technique for digitally encoding analog signal levels.High-resolution counters are used to generate a square wave, and the duty cycle of the squarewave is modulated to encode an analog signal. Typical applications include switching power suppliesand motor control.The Stellaris® PWM module consists of three PWM generator blocks and a control block. The controlblock determines the polarity of the PWM signals, and which signals are passed through to the pins.Each PWM generator block produces two PWM signals that can either be independent signals(other than being based on the same timer and therefore having the same frequency) or a singlepair of complementary signals with dead-band delays inserted. The output of the PWM generationblocks are managed by the output control block before being passed to the device pins.The Stellaris® PWM module provides a great deal of flexibility. It can generate simple PWM signals,such as those required by a simple charge pump. It can also generate paired PWM signals withdead-band delays, such as those required by a half-H bridge driver. Three generator blocks canalso generate the full six channels of gate controls required by a 3-phase inverter bridge.PWM TimerThe timer in each PWM generator runs in one of two modes: Count-Down mode or Count-Up/Downmode. In Count-Down mode, the timer counts from the load value to zero, goes back to the loadvalue, and continues counting down. In Count-Up/Down mode, the timer counts from zero up to theload value, back down to zero, back up to the load value, and so on. Generally, Count-Down modeis used for generating left- or right-aligned PWM signals, while the Count-Up/Down mode is usedfor generating center-aligned PWM signals.The timers output three signals that are used in the PWM generation process: the direction signal(this is always Low in Count-Down mode, but alternates between Low and High in Count-Up/Downmode), a single-clock-cycle-width High pulse when the counter is zero, and a single-clock-cycle-widthHigh pulse when the counter is equal to the load value. Note that in Count-Down mode, the zeropulse is immediately followed by the load pulse.PWM ComparatorsThere are two comparators in each PWM generator that monitor the value of the counter; wheneither match the counter, they output a single-clock-cycle-width High pulse. When in Count-Up/Downmode, these comparators match both when counting up and when counting down; they are thereforequalified by the counter direction signal. These qualified pulses are used in the PWM generationprocess. If either comparator match value is greater than the counter load value, then that comparatornever outputs a High pulse.Figure 15-3 on page 493 shows the behavior of the counter and the relationship of these pulseswhen the counter is in Count-Down mode. Figure 15-4 on page 493 shows the behavior of the counterand the relationship of these pulses when the counter is in Count-Up/Down mode.PWM Signal GeneratorThe PWM generator takes these pulses (qualified by the direction signal), and generates two PWMsignals. In Count-Down mode, there are four events that can affect the PWM signal: zero, load,match A down, and match B down. In Count-Up/Down mode, there are six events that can affectthe PWM signal: zero, load, match A down, match A up, match B down, and match B up. The matchA or matchB events are ignored when they coincide with the zero or load events. If the match Aand match B events coincide, the first signal, PWMA, is generated based only on the match A event,and the second signal, PWMB, is generated based only on the match B event.Dead-Band GeneratorThe two PWM signals produced by the PWM generator are passed to the dead-band generator. Ifdisabled, the PWM signals simply pass through unmodified. If enabled, the second PWM signal islost and two PWM signals are generated based on the first PWM signal. The first output PWM signalis the input signal with the rising edge delayed by a programmable amount. The second outputPWM signal is the inversion of the input signal with a programmable delay added between the fallingedge of the input signal and the rising edge of this new signal.Interrupt/ADC-Trigger SelectorThe PWM generator also takes the same four (or six) counter events and uses them to generatean interrupt or an ADC trigger. Any of these events or a set of these events can be selected as asource for an interrupt; when any of the selected events occur, an interrupt is generated. Additionally,the same event, a different event, the same set of events, or a different set of events can be selectedas a source for an ADC trigger; when any of these selected events occur, an ADC trigger pulse isgenerated. The selection of events allows the interrupt or ADC trigger to occur at a specific positionwithin the PWM signal. Note that interrupts and ADC triggers are based on the raw events; delaysin the PWM signal edges caused by the dead-band generator are not taken into account.Synchronization MethodsThere is a global reset capability that can synchronously reset any or all of the counters in the PWMgenerators. If multiple PWM generators are configured with the same counter load value, this canbe used to guarantee that they also have the same count value (this does imply that the PWMgenerators must be configured before they are synchronized). With this, more than two PWM signalscan be produced with a known relationship between the edges of those signals since the countersalways have the same values.The counter load values and comparator match values of the PWM generator can be updated intwo ways. The first is immediate update mode, where a new value is used as soon as the counterreaches zero. By waiting for the counter to reach zero, a guaranteed behavior is defined, and overlyshort or overly long output PWM pulses are prevented.The other update method is synchronous, where the new value is not used until a global synchronizedupdate signal is asserted, at which point the new value is used as soon as the counter reacheszero. This second mode allows multiple items in multiple PWM generators to be updatedsimultaneously without odd effects during the update; everything runs from the old values until apoint at which they all run from the new values. The Update mode of the load and comparator matchvalues can be individually configured in each PWM generator block. It typically makes sense to usethe synchronous update mechanism across PWM generator blocks when the timers in those blocksare synchronized, though this is not required in order for this mechanism to function properly.Fault ConditionsThere are two external conditions that affect the PWM block; the signal input on the Fault pin andthe stalling of the controller by a debugger. There are two mechanisms available to handle suchconditions: the output signals can be forced into an inactive state and/or the PWM timers can bestopped.Each output signal has a fault bit. If set, a fault input signal causes the corresponding output signalto go into the inactive state. If the inactive state is a safe condition for the signal to be in for anextended period of time, thiskeeps the output signal from driving the outside world in a dangerousmanner during the fault condition. A fault condition can also generate a controller interrupt.Each PWM generator can also be configured to stop counting during a stall condition. The user canselect for the counters to run until they reach zero then stop, or to continue counting and reloading.A stall condition does not generate a controller interrupt.Output Control BlockWith each PWM generator block producing two raw PWM signals, the output control block takescare of the final conditioning of the PWM signals before they go to the pins. Via a single register,the set of PWM signals that are actually enabled to the pins can be modified; this can be used, forexample, to perform commutation of a brushless DC motor with a single register write (and withoutmodifying the individual PWM generators, which are modified by the feedback control loop). Similarly,fault control can disable any of the PWM signals as well. A final inversion can be applied to any ofthe PWM signals, making them active Low instead of the default active High.General-Purpose TimersProgrammable timers can be used to count or time external events that drive the Timer input pins.The Stellaris? General-Purpose Timer Module (GPTM) contains three GPTM blocks (Timer0, Timer1,and Timer 2). Each GPTM block provides two 16-bit timers/counters (referred to as TimerA andTimerB) that can be configured to operate independently as timers or event counters, or configuredto operate as one 32-bit timer or one 32-bit Real-Time Clock (RTC).In addition, timers can be used to trigger analog-to-digital conversions (ADC). The ADC triggersignals from all of the general-purpose timers are ORed together before reaching the ADC module,so only one timer should be used to trigger ADC events.The GPT Module is one timing resource available on the Stellaris? microcontrollers. Other timerresources include the System Timer (SysTick) and the PWM timer in thePWM module.The General-Purpose Timers provide the following features:■Three General-Purpose Timer Modules (GPTM), each of which provides two 16-bittimers/counters. Each GPTM can be configured to operate independently:–As a single 32-bit timer–As one 32-bit Real-Time Clock (RTC) to event capture–For Pulse Width Modulation (PWM)–To trigger analog-to-digital conversions■32-bit Timer modes–Programmable one-shot timer–Programmable periodic timer–Real-Time Clock when using an external 32.768-KHz clock as the input–User-enabled stalling when the controller asserts CPU Halt flag during debug–ADC event trigger■16-bit Timer modes–General-purpose timer function with an 8-bit prescaler (for one-shot and periodic modes only)–Programmable one-shot timer–Programmable periodic timer–User-enabled stalling when the controller asserts CPU Halt flag during debug–ADC event trigger■16-bit Input Capture modes–Input edge count capture270 September 04, 2010Texas Instruments-Production DataGeneral-Purpose Timers–Input edge time capture■16-bit PWM mode–Simple PWM mode with software-programmable output inversion of the PWM signaFunctional DescriptionThe main components of each GPTM block are two free-running 16-bit up/down counters (referredto as TimerA and TimerB), two 16-bit match registers, two prescaler match registers, and two 16-bitload/initialization registers and their associated control functions. The exact functionality of eachGPTM is controlled by software and configured through the register interface.Software configures the GPTM using the GPTM Configuration (GPTMCFG) register,the GPTM TimerA Mode (GPTMTAMR) register and the GPTM TimerB Mode(GPTMTBMR) register. When in one of the 32-bit modes, the timer can only act asa 32-bit timer. However, when configured in 16-bit mode, the GPTM can have its two 16-bit timersconfigured in any combination of the 16-bit modes.8.2.1 GPTM Reset ConditionsAfter reset has been applied to the GPTM module, the module is in an inactive state, and all controlregisters are cleared and in their default states. Counters TimerA and TimerB are initialized to0xFFFF, along with their corresponding load registers: the GPTM TimerA Interval Load(GPTMTAILR) register (see page 296) and the GPTM TimerB Interval Load (GPTMTBILR) register. The prescale counters are initialized to 0x00: the GPTM TimerA Prescale(GPTMTAPR) register (see page 300) and the GPTM TimerB Prescale (GPTMTBPR) register.32-Bit Timer Operating ModesThis section describes the three GPTM 32-bit timer modes (One-Shot, Periodic, and RTC) and theirconfiguration.The GPTM is placed into 32-bit mode by writing a 0 (One-Shot/Periodic 32-bit timer mode) or a 1(RTC mode) to the GPTM Configuration (GPTMCFG) register. In both configurations, certain GPTMregisters are concatenated to form pseudo 32-bit registers. These registers include:■GPTM TimerA Interval Load (GPTMTAILR) register [15:0],■GPTM TimerB Interval Load (GPTMTBILR) register [15:0],■GPTM TimerA (GPTMTAR) register [15:0],■GPTM TimerB (GPTMTBR) register [15:0],In the 32-bit modes, the GPTM translates a 32-bit write access to GPTMTAILR into a write accessto both GPTMTAILR and GPTMTBILR. The resulting word ordering for such a write operation is: GPTMTBILR[15:0]:GPTMTAILR[15:0]Likewise, a read access to GPTMTAR returns the value:GPTMTBR[15:0]:GPTMTAR[15:0]8.2.2.1 32-Bit One-Shot/Periodic Timer ModeIn 32-bit one-shot and periodic timer modes, the concatenated versions of the TimerA and TimerBregisters are configured as a 32-bit down-counter. The selection of one-shot or periodic mode isdetermined by the value written to the TAMR field of the GPTM TimerA Mode (GPTMTAMR) register, and there is no need to write to the GPTM TimerB Mode (GPTMTBMR) register.When software writes the TAEN bit in the GPTM Control (GPTMCTL) register, theimer begins counting down from its preloaded value. Once the 0x0000.0000 state is reached, thetimer reloads its start value from the concatenated GPTMTAILR on the next cycle. If configured tobe a one-shot timer, the timer stops counting and clears the TAEN bit in the GPTMCTL register. Ifconfigured as a periodic timer, it continues counting.In addition to reloading the count value, the GPTM generates interrupts and triggers when it reachesthe 0x000.0000 state. The GPTM sets the TATORIS bit in the GPTM Raw Interrupt Status(GPTMRIS) register andholds it until it is cleared by writing the GPTM InterruptClear (GPTMICR) register. If the time-out interrupt is enabled in the GPTM InterruptMask (GPTMIMR) register (see page 290), the GPTM also sets the TATOMIS bit in the GPTM MaskedInterrupt Status (GPTMMIS) register (see page 293). The ADC trigger is enabled by setting theTAOTE bit in GPTMCTL.If software reloads the GPTMTAILR register while the counter is running, the counter loads the newvalue on the next clock cycle and continues counting from the new value.If the TASTALL bit in the GPTMCTL register is set, the timer freezes counting while the processoris halted by the debugger. The timer resumes counting when the processor resumes execution.32-Bit Real-Time Clock Timer ModeIn Real-Time Clock (RTC) mode, the concatenated versions of the TimerA and TimerB registersare configured as a 32-bit up-counter. When RTC mode is selected for the first time, the counter isloaded with a value of 0x0000.0001. All subsequent load values must be written to the GPTM TimerAMatch (GPTMTAMATCHR) register by the controller.The input clock on an even CCP input is required to be 32.768 KHz in RTC mode. The clock signalis then divided down to a 1 Hz rate and is passed along to the input of the 32-bit counter.When software writes the TAEN bit inthe GPTMCTL register, the counter starts counting up from itspreloaded value of 0x0000.0001. When the current count value matches the preloaded value in theGPTMTAMA TCHR register, it rolls over to a value of 0x0000.0000 and continues counting untileither a hardware reset, or it is disabled by software (clearing the TAEN bit). When a match occurs,the GPTM asserts the RTCRIS bit in GPTMRIS. If the RTC interrupt is enabled in GPTMIMR, theGPTM also sets the RTCMIS bit in GPTMMIS and generates a controller interrupt. The status flagsare cleared by writing the RTCCINT bit in GPTMICR.If the TASTALL and/or TBSTALL bits in the GPTMCTL register are set, the timer does not freeze ifthe RTCEN bit is set in GPTMCTL.16-Bit Timer Operating ModesThe GPTM is placed into global 16-bit mode by writing a value of 0x4 to the GPTM Configuration(GPTMCFG) register. This section describes each of the GPTM 16-bit modes ofoperation. TimerA and TimerB have identical modes, so a single description is given using an n toreference both.16-Bit One-Shot/Periodic Timer ModeIn 16-bit one-shot and periodic timer modes, the timer is configured as a 16-bit down-counter withan optional 8-bit prescaler that effectively extends the counting range of the timer to 24 bits. Theselection of one-shot or periodic mode is determined by the value written to the TnMR field of theGPTMTnMR register. The optional prescaler is loaded into the GPTM Timern Prescale (GPTMTnPR)register.When software writes the TnEN bit in the GPTMCTL register, the timer begins counting down fromits preloaded value. Once the 0x0000 state is reached, the timer reloads its start value froGPTMTnILR and GPTMTnPR on the next cycle. If configured to be a one-shot timer, the timer stopscounting and clears the TnEN bit in the GPTMCTL register. If configured as a periodic timer, itcontinues counting.In addition to reloading the count value, the timer generates interrupts and triggers when it reachesthe 0x0000 state. The GPTM sets the TnTORIS bit in the GPTMRIS register, and holds it until it iscleared by writing the GPTMICR register. If the time-out interrupt is enabled in GPTMIMR, the GPTMalso sets the TnTOMIS bit in GPTMISR and generates a controller interrupt. The ADC trigger isenabled by setting the TnOTE bit in the GPTMCTL register.If software reloads the GPTMTAILR register while the counter is running, the counter loads the newvalue on the next clock cycle and continues counting from the new value.If the TnSTALL bit in the GPTMCTL register is set, the timer freezes counting while the processoris halted by the debugger. The timer resumes counting when the processor resumes execution.16-Bit Input Edge Count ModeIn Edge Count mode, the timer is configured as a down-counter capable of capturing three typesof events: rising edge, falling edge, or both. To place the timer in Edge Count mode, the TnCMR bitof the GPTMTnMR register must be set to 0. The type of edge that in theGPTMTnILR register and the GPTMTnMA TCHR register equals the number of edge events thatmust be counted.When software writes the TnEN bit in the GPTM Control (GPTMCTL) register, the timer is enabledfor event capture. Each input event on the CCP pin decrements the counter by 1 until the event countmatches GPTMTnMA TCHR. When the counts match, the GPTM asserts the CnMRIS bit in theGPTMRIS register (and the CnMMIS bit, if the interrupt is not masked).The counter is then reloaded using the value in GPTMTnILR, and stopped since the GPTMautomatically clears the TnEN bit in the GPTMCTL register. Once the event count has been reached,all further events are ignored until TnEN is re-enabled by software.16-Bit Input Edge Time ModeIn EdgeTime mode, the timer is configured as a free-running down-counter initialized to the valueloaded in the GPTMTnILR register (or 0xFFFF at reset). This mode allows for event capture ofeither rising or falling edges, but not both. The timer is placed into Edge Time mode by setting theTnCMR bit in the GPTMTnMR register, and the type of event that the timer captures is determinedby the TnEVENT fields of the GPTMCTL register.When software writes the TnEN bit in the GPTMCTL register, the timer is enabled for event capture.When the selected input event is detected, the current Tn counter value is captured in the GPTMTnRregister and is available to be read by the controller. The GPTM then asserts the CnERIS bit (andthe CnEMIS bit, if the interrupt is not masked).After an event has been captured, the timer does not stop counting. It continues to count until theTnEN bit is cleared. When the timer reaches the 0x0000 state, it is reloaded with the value from theGPTMTnILR register.16-Bit PWM ModeThe GPTM supports a simple PWM generation mode. In PWM mode, the timer is configured as adown-counter with a start value (and thus period) defined by GPTMTnILR. In this mode, the PWMfrequency and period are synchronous events and therefore guaranteed to be glitch free. PWMmode is enabled with the GPTMTnMR register by setting the TnAMS bit to 0x1, the TnCMR bit to0x0, and the TnMR field to 0x2.When software writes the TnEN bit in the GPTMCTL register, the counter begins counting downuntil it reaches the 0x0000 state. On the next counter cycle, the counter reloads its start value fromGPTMTnILR and continues counting until disabled by software clearing the TnEN bit in the GPTMCTLregister. No interrupts or status bits are asserted in PWM mode.The output PWM signal asserts when the counter is at the value of the GPTMTnILR register (itsstart state), and is deasserted when the counter value equals the value in the GPTM Timern MatchRegister (GPTMTnMATCHR). Software has the capability of inverting the output PWM signal bysetting the TnPWML bit in the GPTMCTL register.。
开关电源外文翻译(1)
Modeling, Simulation, and Reduction of Conducted Electromagnetic Interference Due to a PWM Buck Type SwitchingPower 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 ofa 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 I cm1 and I cm2 and the related current paths []9. The power electronics converters performas noise source between 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 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 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 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 powerelectronics 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.For a simple fixed frequency PWM controller that is applied to a Buck DC/DC) changes slow with respect converter, it is possible to assume the error voltage (veto the switching frequency, the pulse 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 power supply, 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 Veas is shown in (2).with amplitude of Ve1fm 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) as it short circuit and converter is replaced by PWM waveform switch current (Iexhas shown in Fig. 10.The 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 kHz The 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 isdesired 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 D 1. The EMI spectrum was simulated with D 1=0.05. Simulations are repeated with D 1=0.01 and 0.25 and the resultsare shown in Fig.14 and 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=5000Hz that lead to 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 an d Design” 3rd edition, 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 Su pplies”, Session 3B, IEEE International Symp. on EMC, 1986.[4] Henderson, R. D. and Rose, P. J., “Harmonics and their Effects on Power Quality and Transformers”, IEEE Trans. On Ind. App., 1994, pp. 528-532.[5] I. Kasikci, “A New Method for Power Facto r 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 Co mpatibility, Page(s): 211-216, 23-25 May 1989.作者：A. Farhadi国籍：伊朗出处：10.11.248.20:8000/rewriter/EI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：10.11.248.20:8000/rewriter/EI摘要：电子设备之中杂乱的辐射或者能量叫做电磁干扰(EMI)。
高频开关电源设计
毕业论文（设计）题目：高频开关电源设计（英文）：High Frequency Switching PowerSupply院别：自动化学院专业：电气工程及其自动化姓名：学号：指导教师：日期：摘要本文分析了国内外高频开关电源的发展和现状，研究了高频开关电源的基本原理以及高频开关电源在电力直流操作电源系统中的应用，设计出一种实用于电力系统的高频开关电源，以替代传统的相控电源。
该系统以MOSFET作为功率开关器件，构成桥式BACK开关变换器，采用脉宽调制PWM技术，PWM控制信号由集成控制器UC3825产生，从输出实时采样电压反馈信号，以控制输出电压的变化，控制电路和主电路之间通过变压器或光电藕合器进行隔离，并设计了软启动和过流保护电路。
通过实验证明该系统能安全、可靠运行，达到了设计要求。
【关键词】:高频开关电源，Buck变换器，PWM，MOSFETAbstraCtThe PaPer analyze the Present situation and development o f h1gh_frequeney Switehing power supply(HF SPS) domestieally and overseas，study and researeh the basal prineiple of HF SPS and its applieation in electric power system，then design HF SPS applied in e1eetric power system in order to replace the old supply controlled by phase angle。
The buek full_brige converter is made of four MOSFET，and the theory of PWM is used。
The signal of PWM is offered by controller UC3825. The feedbaek voltage achieved from output is used to control the change of the output.The primary circuit and the control cireuit are insulated by transformer or photocoupler. The Soft_Start and the Over Current Self_protcetion are also designed。
开关电源功率因数校正电路设计外文资料翻译..
三江学院毕业设计（论文）外文资料翻译学生姓名：邱圣杰指导教师：陈刚讲师所在系部：电气与自动化工程学院专业名称：电气工程及其自动化学生学号； 12011071044 指导老师评语：指导老师签名：年月日1.外文资料翻译译文反激式功率因数校正电路的电磁兼容设计通过反激式功率因数校正电路说明了单级功率因数校正电路中的电磁兼容问题，分析了单级功率因数校正电路中骚扰的产生机理，给出了电磁兼容的设计，最后提出了其他几种减少电磁干扰的方法。
电磁兼容（EMC）是指电子设备或系统在其电磁环境中能正常工作且不对该环境中任何事物构成不能承受的电磁骚扰的能力。
随着电子产品越来越多地采用低功耗、高速度、高集成度的LSI电路，而使得这些装置比以往任何时候更容易受到电磁干扰的威胁。
而与此同时，大功率家电及办公自动化设备的增多，以及移动通信、无线寻呼的广泛应用等，又大大增加了电磁骚扰源。
这些变化迫使人们把电磁兼容作为重要的技术问题加以关注。
特别是欧共体将产品的电磁兼容性要求纳入技术法规，强制执行89/336/EEC指令，即规定从1996年1月1日起电气和电子产品都必须符合EMC要求，并加贴CE标志后才能在欧共体市场上销售以来，促使了各国政府从国际贸易的角度，高度重视电磁兼容技术。
开关电源具有体积小、重量轻、效率高的优点，且市场上已有开关电源集成控制模块，这使电源设计、调试简化了许多，所以，在大多数的电子设备（如计算机、电视机及各种控制系统）中得到了广泛的应用。
然而，开关电源自身产生的各种噪声却使其成了一个很强的电磁骚扰源。
这些骚扰随着开关频率的提高、输出功率的增大而明显地增强，对电子设备的正常运行构成了潜在的威胁。
因此，只有提高开关电源的电磁兼容性，才能使开关电源在那些对电源噪声指标有严格要求的场合被采用。
电磁兼容包括两个方面的含义。
1、电子设备或系统内部的各个部件和子系统、一个系统内部的各台设备乃至相邻几个系统，在它们自己所产生的电磁环境及在他们所处的外界电磁环境中，能按原设计要求正常运行。
高频开关电源的工作原理
推挽电路原理图
V1
W1
- Uin +
V2
W2
Uce 2Uin
L
Uin
+
0
Ton
Toff
t
Ic
0
T
t
4、半桥电路
半桥电路有两个功率开关管，通过两个串连的电容器来构成 工作回路，这两个功率管交替导通驱动高频变压器进行能量 传递，变压器是双向激励的。半桥电路同样存在变压器磁偏 现象，会出现“直通”问题。同样的变压器的情况，半桥的 输出功率大于推挽电路。如下图所示：C1和C2的作用主要是 实现静态时分压，使Ua=1/2Uin。当V1导通，V2截止时， 输入电流方向为图中虚线方向，向C2充电；当V1截止，V2 导通时，输入电流方向为图中实线方向，向C1充电。当V1导 通，V2截止时，V2两端承受的电压为输入直流电压Uin。
APFC电路，是有源功率因数校正电路。它是一
个升压电路，电路结构采用的是BOOT电路，输出电压
一般规定在410VDC左右。由于开关电源所采用的器件 全部工作在非线性状态，电路上有电感和电容，所以会 造成交流输入电压和电流的相位存在相位差，导致交流 电不能全部做功，一部分在电感和电容中转换。另外交 流电压和电流波形出现畸变，造成谐波分量增加，干扰 增加。功率因数校正电路就是将电压和电流相位强制到 一致，同时对波形给予修正。
高频开关电源工作原理
作者：湖南常德分公司传动中心郝书韬
1、开关电源的概念 2、开关电源的组成 3、开关电源的常用电路类型与原理 4、通信用开关电源的基本要求
1、开关电源的概念
开关电源是一个能量转换器，作为电源的功率器件工作 在开关状态（开关管、电感、高频变压器、电容、整流 二极管）－开或关状态，其特点是频率高、功耗低、工 作效率高、体积小、输入范围宽(SwitchingRegulator -- A switching circuit that operates in a closed loopsystem to regulate the power supply output) 通过闭环系统调节，使输出电压保持稳定。
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。
高频开关电源工作原理
波分量增加，干扰增加。功率因数校正电路就是将电压和电流相位强制
7
到一致，同时对波形给予修正。
8
二、开关电源的电路组成
二、开关电源的电路组成
开关电源APFC电路
二、开关电源的电路组成
输入缓启动电路原理图
将PFC输出的410VDC高压进行变换，变成高频高压脉冲电压，然后驱 动高频变压器，变压器将高压脉冲电压变成低压脉冲电压。该部分的主 要器件是开关功率器件和高频变压器。
开关电源的主要指标
一、开关电源的概念
4、开关电源的主要指标 ④负载调整率 指的是输出负载变化时，引起的输出电压的变化。 SL＝（△V0÷V0 ）％。 ⑤输出纹波（峰－峰值） 这个指标衡量了开关电源的电磁兼容性，纹波越小越好。一般小于输 出电压的百分之三毫伏，例如对于53.5V电压来说，输出纹波就位150毫 伏。
三、开关电源的常用电路类型
正激电路原理图（单管正激）
三、开关电源的常用电路类型
正激电路原理图（双管正激）
推挽式功率变换电路原理图，如图下图所示。推挽电路要求输入电压
1
低，两个开关管的耐压要求是输入电压的2倍，所以一般用在DC/DC电源
2
中。推挽电路一般用在中型功率电路上，变压器双向激励，变压器效率
02
％，工作频率是振荡频率的一半，所使用的控制芯片一般是UC3844和
03
UC3845。可以做中型功率的开关电源，使用双管正激电路，其功率可以
04
做得更高一点。虽然功率变压器不像反激式电路要开气隙，但是一般要
05
在变压器中加去磁绕组，在关断时将付边的能量反射到交流输入上。
06
单端正激电路
三、开关电源的常用电路类型
电源
高频开关电源电路原理(中英文对照)高频开关电源由以下几个部分组成：一、主电路从交流电网输入、直流输出的全过程，包括：1、输入滤波器：其作用是将电网存在的杂波过滤，同时也阻碍本机产生的杂波反馈到公共电网。
2、整流与滤波：将电网交流电源直接整流为较平滑的直流电，以供下一级变换。
3、逆变：将整流后的直流电变为高频交流电，这是高频开关电源的核心部分，频率越高，体积、重量与输出功率之比越小。
4、输出整流与滤波：根据负载需要，提供稳定可靠的直流电源。
二、控制电路一方面从输出端取样，经与设定标准进行比较，然后去控制逆变器，改变其频率或脉宽，达到输出稳定，另一方面，根据测试电路提供的资料，经保护电路鉴别，提供控制电路对整机进行各种保护措施。
三、检测电路除了提供保护电路中正在运行中各种参数外，还提供各种显示仪表资料。
四、辅助电源提供所有单一电路的不同要求电源。
开关控制稳压原理开关K以一定的时间间隔重复地接通和断开，在开关K接通时，输入电源E通过开关K和滤波电路提供给负载RL，在整个开关接通期间，电源E向负载提供能量；当开关K断开时，输入电源E便中断了能量的提供。
可见，输入电源向负载提供能量是断续的，为使负载能得到连续的能量提供，开关稳压电源必须要有一套储能装置，在开关接通时将一部份能量储存起来，在开关断开时，向负载释放。
图中，由电感L、电容C2和二极管D组成的电路，就具有这种功能。
电感L用以储存能量，在开关断开时，储存在电感L 中的能量通过二极管D释放给负载，使负载得到连续而稳定的能量，因二极管D使负载电流连续不断，所以称为续流二极管。
在AB间的电压平均值EAB可用下式表示：EAB=TON/T*E式中TON为开关每次接通的时间，T为开关通断的工作周期（即开关接通时间TON和关断时间TOFF之和）。
由式可知，改变开关接通时间和工作周期的比例，AB间电压的平均值也随之改变，因此，随着负载及输入电源电压的变化自动调整TON和T的比例便能使输出电压V0维持不变。
高频开关电源的基本原理
高频开关电源的基本原理高频开关电源的基本原理高频开关电源的基本原理是什么？高频开关电源是通过高频功率变换技术，将直流或整流后的直流电压斩波成频率很高的脉冲电压加到变压器上，经变压及整流滤波输出，最终变成各种需要的稳定直流电压。
由于脉冲电压频率相比交流工频大大提高，变压器和滤波电感等磁性元件的体积和重量就大大缩小，同时效率也明显提高。
什么是“APFC”？“APFC”是英文Active Power Factor Correction 的字头缩写，即有源功率因数校正。
该技术是通过高频功率变换技术(通常为Boost 变换器)使交流输入电流完全跟随交流输入电压做正弦变化，功率因数接近于1，大大减小了开关电源对交流电网的谐波干扰。
什么是功率限制？功率限制是指电源模块的最大输出功率为一固定值。
在模块的输出电压变化时，电压与其输出电流的乘积(即输出功率)最大不会超过该固定值。
此功能在过载情况下最有用处，如对过放电的蓄电池快速充电或系统中某一个或几个电源模块出故障等，保护电源模块免受过载造成的损坏。
什么是“MTBF”？“MTBF”是英文 Mean-Time Between failure的字头缩写，即“平均无故障时间” 。
它是可靠性预计指标，用来表示设备的长期工作可靠性。
由于是预计指标，通常是用理论计算来得出。
具体清参考YD/T282-2000标准的第六章内容。
什么是“N+1”备份？“N+1”备份是电源系统提高可靠性的一种工作方式。
若系统最大需求（包括最大负载和电池充电）为N个电源模块并联工作，为防止某个模块损坏而影响系统的最大输出能力，在系统N个模块的基础上再多加一个模块工作，使系统可靠性更高。
什么是“热插拔”？即当电源模块插入或拔出机架系统时，不需中断整个系统的运行，便可方便的将电源模块投入或撤出系统工作。
尽管产品允许"热插拔"操作，但还是建议用户在日常维护中，一般应先断掉待操作电源模块的交流输入（如有可能，直流输出开关也断掉），再进行操作，以便取得更好的维护效果。
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High-frequency switching powerSupply circuit of high frequency switching power supply from the following components : first. a main circuit from the exchange network input, DC output of the entire process, including : an import filter : its role is to network the clutter filtration, but also hindered the plane of the clutter feedback to the public grid. 2, rectifier and filter : direct AC power rectifier for smoother DC, for under a transformation. 3, the inverter : Rectifier the high frequency alternating current into direct current, high-frequency switching power supply is the core component of the higher frequency, size, weight and output ratio smaller. 4, and the rectifier output filter : Under load the need to provide stable and reliable DC power supply.Second, the control circuit while output from the sample, with the set standards, then controlled inverter, change its frequency or pulse width output achieve stability, on the other hand, according to test data provided by the circuit by circuit protection identification, Control circuit for the unit for various protection measures.Third, in addition to providing detection circuit protection circuit is running various parameters, but also provide information display instruments.Fourth, the auxiliary power supply circuit for the single power supply to the different requirements.Switching regulator control principleSwitching Control Switching Regulators K principle to a certain time interval repeatedly connected and disconnected, connected to the switch K, Input voltage E and K through switching circuit filter to load RL, the entire switch connected, Power E to provide energy load; When K disconnect switch, the input power is interrupted E. energy delivery. This shows that the importation of power to provide energy load is intermittent, for the load can be provided for the energy, Switching power supply must be a set of storage devices, the switches will be connected to a part of the energy stored in the switch disconnected. Load to the release. Map from the inductance L, capacitance diode D and C2 components of the circuit, it is such a function. Inductor L for energy storage in switch disconnected, stored in the inductor L of energy release through diodes D to load, so that load is continuous and stable energy, diode D enable continuous load current, known as the continued flow diode. AB in the average voltage EAB can be given by : EAB=TON/T*E where TON connected to the switch each time, T-off switch for the cycle (that is, access time TON switch and turn-off time and TOFF's). - We can see from the change switch connected to the work cycle time and the ratio of the voltage between the AB average change also, therefore, With the load and input supply voltage changes and automatically adjust TON T ratio, it will cause the output voltage V0 unchanged. Change the access time and cycle TON percentage change is the pulse duty cycle. This method, known as "time ratio control" (Time Ratio Control, for the initials TRC). TRC under control principle, there are three ways : 1. Pulse width modulation (Pulse Width Modulation, acronym for PWM) switching constant cycle by changing the pulse width to change the duty cycle approaches. 2, pulse frequency modulation (Pulse Frequency Modulation, acronym for the PFM) conduction pulse width constant by changing the switching frequency tochange the duty cycle approaches. 3, mixed conduction modulation and pulse width switching frequency not fixed are, they change the way It is more than two hybrid models.SMPS developments and trends in the United States in 1955 Roje (GH.Roger) invention of the self-excited oscillation push redeem transistor single transformer DC converters, high-frequency conversion is the beginning of control circuit, 1957 United States investigation tournament (Jen Sen) since the invention of the push-pull double Flyback transformers, 1964 American scientists proposes to abolish the frequency transformer series switching power supply scenario, This power to the right size and weight of the decline was a fundamental way. To the 1969 high-power silicon transistor because the pressure increase diode reverse recovery time shortened, and other components improve, and finally turned into a 25 kHz switching power supply.Currently, switching power supply to small, Light volume and the characteristics of high efficiency has been widely used in electronic computer-driven variety of terminal equipment, Communications equipment almost all electronic equipment, the electronic information industry indispensable to the rapid development of a power mode. Currently the market for sale in the switching power supply using bipolar transistors made of 100kHz. use made of 500kHz MOS power, though practical, but its frequency to be further enhanced. To improve the switching frequency, it is necessary to reduce the switching loss, and to reduce the switching loss, you need to have high-speed switching devices. However, the switching speed, will be affected by the circuit inductance and capacitance diode or stored charge arising from the impact of the surge or noise. This will not only affect the surrounding electronic equipment, but also greatly reduce the reliability of the power supply itself. Among them, with the switch to prevent Kai-closed by the voltage surge, it is R-C or L-C Composite bumpers, and the storage charge by the diode current surge caused by the use made of amorphous cores such as magnetic bumper. However, the high frequency of 1 MHz and above, using resonant circuit, Switch to enable the voltage or current through the switch was a sine, which could reduce the switching loss, This can also control the surge occurred. Switches such as resonant mode switching. Currently such SMPS of very active, because this means no significant increase switching speed can theoretically put switching loss fall to zero. and the noise is small, is expected to become high-frequency switching power supply of one of the main ways. At present, many countries in the world are working on several trillion Hz converter practical research.高频开关电源电路原理高频开关电源由以下几个部分组成：一、主电路从交流电网输入、直流输出的全过程，包括：1、输入滤波器：其作用是将电网存在的杂波过滤，同时也阻碍本机产生的杂波反馈到公共电网。