逆变器论文英文文献

Inverter may refer toInverter (electrical), a device that converts direct current to alternating current Inverter (air conditioning), an air conditioner that can continuously regulate its output by altering the compressor speed in response to cooling demand Uninterruptible power supply, which often are based on an electrical inverter Inverter (logic gate), a logic gate also called a NOT gate Inverter (electrical)An inverter is an electrical device that converts direct current (DC) to alternating current (AC); the converted AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control inverters have no moving parts and are used in a wide range of applications, from small switching power supplies in computers, to large electric utility high-voltage direct current applications that transport bulk power. Inverters are commonly used to supply AC power from DC sources such as solar panels or electrical inverter is a high-power electronic oscillator. It is so named because early mechanical AC to DC converters were made to work in reverse, and thus were "inverted", to convert DC to inverter performs the opposite function of a power source utilizationAn inverter converts the DC electricity from sources such as batteries, solar panels, or fuel cells to AC electricity. The electricity can be at any required voltage; in particular it can operate AC equipment designed for mains operation, or rectified to produce DC at any desired tie inverters can feed energy back into the distribution network because they produce alternating current with the same wave shape and frequency as supplied by the distribution system. They can also switch off automatically in the event of a convert direct current from individual solar panels into alternating current for the electric power suppliesAn uninterruptible power supply (UPS) uses batteries and an inverter to supply AC power when main power is not available. When main power is restored, a rectifier is used to supply DC power to recharge the heatingInverters convert low frequency main AC power to a higher frequency for use in induction heating. To do this, AC power is first rectified to provide DC power. The inverter then changes the DC power to high frequency AC power.[edit] HVDC power transmissionWith HVDC power transmission, AC power is rectified and high voltage DC power is transmitted to another location. At the receiving location, an inverter in a static inverter plant converts the power back to AC.[edit] Variable-frequency drivesMain article: variable-frequency driveA variable-frequency drive controls the operating speed of an AC motor by controlling the frequency and voltage of the power supplied to the motor. An inverter provides the controlled power. In most cases, the variable-frequency drive includes a rectifier so that DC power for the inverter can be provided from main AC power. Since an inverter is the key component, variable-frequency drives are sometimes called inverter drives or just inverters.[edit] Electric vehicle drivesAdjustable speed motor control inverters are currently used to power the traction motors in some electric and diesel-electric rail vehicles as well as some battery electric vehicles and hybrid electric highway vehicles such as the Toyota Prius. Various improvements in inverter technology are being developed specifically for electric vehicle applications.[2] In vehicles with regenerative braking, the inverter also takes power from the motor (now acting as a generator) and stores it in the batteries.[edit] Air conditioningMain article: Inverter (air conditioning)An air conditioner bearing the inverter tag uses a variable-frequency drive to control the speed of the motor and thus the compressor.[edit] The general caseA transformer allows AC power to be converted to any desired voltage, but at the same frequency. Inverters, plus rectifiers for DC, can be designed to convert from any voltage, AC or DC, to any other voltage, also AC or DC, at any desired frequency. The output power can never exceed the input power, but efficiencies can be high, with a small proportion of the power dissipated as waste low power inverters have a warning not to use conventional fluorescent lighting. This is due to the power correction capacitor connected in parallel with the lamp. Removing the capacitor will fix the problem. What may not be known is that in dual lamp fittings the capacitor may be connected in series with the second lamp, thus removing the problem as well as the stroboscopic effect caused by the mains designsIn one simple inverter circuit, DC power is connected to a transformer through the centre tap of the primary winding. A switch is rapidly switched back and forth to allow current to flow back to the DC source following two alternate paths through one end of the primary winding and then the other. The alternation of the direction of current in the primary winding of the transformer produces alternating current (AC) in the secondary electromechanical version of the switching device includes two stationary contacts and a spring supported moving contact. The spring holds the movable contact against one of the stationary contacts and an electromagnet pulls the movable contact to the opposite stationary contact. The current in the electromagnet is interrupted by the action of the switch so that the switch continually switches rapidly back and forth. This type of electromechanical inverter switch, called a vibrator or buzzer, was once used in vacuum tube automobile radios. A similar mechanism has been used in door bells, buzzers and tattoo they became available with adequate power ratings, transistors and various other types of semiconductor switches have been incorporated into inverter circuit designs.[edit] Output waveformsThe switch in the simple inverter described above, when not coupled to an output transformer, produces a square voltage waveform due to its simple off and on nature as opposed to the sinusoidal waveform that is the usual waveform of an AC power supply. Using Fourier analysis, periodic waveforms are represented as the sum of an infinite series of sine waves. The sine wave that has the same frequency as the original waveform is called the fundamental component. The other sine waves, called harmonics, that are included in the series have frequencies that are integral multiples of the fundamental quality of the inverter output waveform can be expressed by using the Fourier analysis data to calculate the total harmonic distortion (THD). The total harmonic distortion is the square root of the sum of the squares of the harmonic voltages divided by the fundamental voltage:The quality of output waveform that is needed from an inverter depends on the characteristics of the connected load. Some loads need a nearly perfect sine wave voltage supply in order to work properly. Other loads may work quite well with a square wave voltage.[edit] Advanced designs H-bridge inverter circuit with transistor switches and antiparallel diodesThere are many different power circuit topologies and control strategies used in inverter designs. Different design approaches address various issues that may be more or less important depending on the way that the inverter is intended to be issue of waveform quality can be addressed in many ways. Capacitors and inductors can be used to filter the waveform. If the design includes a transformer, filtering can be applied to the primary or the secondary side of the transformer or to both sides. Low-pass filters are applied to allow the fundamental component of the waveform to pass to the output while limiting the passage of the harmonic components. If the inverter is designed to provide power at a fixed frequency, a resonant filter can be used. For an adjustable frequency inverter, the filter must be tuned to a frequency that is above the maximum fundamental most loads contain inductance, feedback rectifiers or antiparallel diodes are often connected across each semiconductor switch to provide a path for the peak inductive load current when the switch is turned off. The antiparallel diodes are somewhat similar to the freewheeling diodes used in AC/DC converter analysis reveals that a waveform, like a square wave, that is antisymmetrical about the 180 degree point contains only odd harmonics, the 3rd, 5th, 7th etc. Waveforms that have steps of certain widths and heights eliminate or “cancel” additional harmonics. For example, by inserting a zero-voltage step between the positive and negative sections of the square-wave, all of the harmonics that are divisible by three can be eliminated. That leaves only the 5th, 7th, 11th, 13th etc. The required width of the steps is one third of the period for each of the positive and negative steps and one sixth of the period for each of the zero-voltage the square wave as described above is an example of pulse-width modulation (PWM). Modulating, or regulating the width of a square-wave pulse is often used as a method of regulating or adjusting an inverter's output voltage. When voltage control is not required, a fixed pulse width can be selected to reduce or eliminate selected harmonics. Harmonic elimination techniques are generally applied to the lowest harmonics because filtering is more effective at high frequencies than at low frequencies. Multiple pulse-width or carrier based PWM control schemes produce waveforms that are composed of many narrow pulses. The frequency represented by the number of narrow pulses per second is called the switching frequency or carrier frequency. These control schemes are often used in variable-frequency motor control inverters because they allow a wide range of output voltage and frequency adjustment while also improving the quality of the inverters provide another approach to harmonic cancellation. Multilevel inverters provide an output waveform that exhibits multiple steps at several voltage levels. For example, it is possible to produce a more sinusoidal wave by having split-rail direct current inputs at two voltages, or positive and negative inputs with a central ground. By connecting the inverter output terminals in sequence between the positive rail and ground, the positive rail and the negative rail, the ground rail and the negative rail, then both to the ground rail, a stepped waveform is generated at the inverter output. This is an example of a three level inverter: the two voltages and ground.[3][edit] Three phase inverters 3-phase inverter with wye connected loadThree-phase inverters are used for variable-frequency drive applications and for high power applications such as HVDC power transmission. A basic three-phase inverter consists of three single-phase inverter switches each connected to one of the three load terminals. For the most basic control scheme, the operation of the three switches is coordinated so that one switch operates at each 60 degree point of the fundamental output waveform. This creates a line-to-line output waveform that has six steps. The six-step waveform has a zero-voltage step between the positive and negative sections of the square-wave such that the harmonics that are multiples of three are eliminated as described above. When carrier-based PWM techniques are applied to six-step waveforms, the basic overall shape, or envelope, of the waveform is retained so that the 3rd harmonic and its multiples are inverter switching circuit showing 6-step switching sequence and waveform of voltage between terminals A and CTo construct inverters with higher power ratings, two six-step three-phase inverters can be connected in parallel for a higher current rating or in series for a higher voltage rating. In either case, the output waveforms are phase shifted to obtain a 12-step waveform. If additional inverters are combined, an 18-step inverter is obtained with three inverters etc. Although inverters are usually combined for the purpose of achieving increased voltage or current ratings, the quality of the waveform is improved as well.

一种新颖的用于消除PWM逆变器输出共模电压的有源滤波器题目是这个意思，原文在哪里啊找到了貌似是这个，是个论文PWM逆变器在应用中会产生共模电压, 共模电压在IGBT的高速开关期间产生充放电电流。此电流通过电机内部的寄生电容产生流入地线的漏电流。漏电流过大将对电源产生电磁干扰，还会使电机轴承过早毁坏，从而影响系统运行的可靠性。文中提出了一种新颖的可以有效消除脉冲宽度调制（PWM）逆变器产生的共模电压的有源滤波器。这个有源滤波器由一个单相逆变器和一个五绕组共模变压器组成，可以产生与PWM逆变器输出的电压幅值相等，相位相反的共模电压，通过五绕组共模变压器叠加到逆变器输出中，从而有效消除感应电机端的共模电压。这种有源滤波器结构简单，控制容易。文中通过理论分析，仿真和实验结果证明了这种结构的有效性。关键词：PWM逆变器；输出有源滤波器; 共模电压; 五绕组变压器引言：高速电力半导体器件如绝缘栅双极晶体管(IGBT)的发展使电压源型脉宽调制逆变器的载波频率大大提高（如20 kHz），高开关频率以及零开关损耗方案可显著提高PWM变频器的性能。但在PWM变频器的应用中，出现了一些负面问题。 例如，传统的IGBT的控制策略使PWM逆变器输出产生了共模电压。共模电压使IGBT在高速开关期间，产生充放电电流。电流通过电机内部的寄生电容产生流入地线的漏电流，漏电流过大将引起电机保护电路的误动作；频率从100 kHz到几兆范围变化的漏电流经地线流回系统的三相电源中，产生电磁干扰(EMI) ，影响电网上的其他设备的正常运行；轴电压和轴承电流过大使电机轴承过早毁坏[1,2] 。
为抑制逆变器输出的共模电压，提高系统的可靠性，传统的方法是采用转轴接地，轴承绝缘，具有传导性的润滑剂等来降低轴电流，保护电机轴承，但是电机端共模电压仍然存在。电机负载运行时，共模电压仍会通过负载轴承产生具有破坏性的电流。为此开始采用由无源器件组成的滤波器[3,4]，这类方法对消除过电压的影响非常有效，但载波频率发生变化时，对降低逆变器输出中的谐波成分的作用非常有限。因此，近年来开始尝试用有源器件来消除这些负面影响。Alexander Julian等提出了四相逆变器来消除共模电压[5]，这种方法会产生严重的开关损耗和谐波失真。Annette Jouanne提出双桥逆变器(DBI)用于消除电机共模电压和由此产生的轴承漏电流[6]，这种方法增加了一个三相逆变器及相应的驱动设备，所采用电机的定子必须有两套绕组，从而限制了这种方法的应用范围。日本学者Satoshi Ogasawara等人提出了一种有源共模噪声消除器(ACC)方案用于消除共模电压[7]，效果非常理想，但是这种方法需要射极跟随器，限制了其在高电压中应用。 提出了有源共模电压补偿器(ACCom)用于降低PWM VSI驱动感应电机系统中的轴电流[8]，这种结构的滤波器的变压器原边由具有6个开关器件组成的四电平半桥逆变器驱动，由于元件的数量很多并且驱动这些元件的电路非常复杂，因此串联电容的电压平衡问题没有解决，此文仅给出了仿真结果。
本文提出了一种新颖的逆变器输出有源滤波器来消除共模电压，从理论上分析了这种结构的滤波器的工作原理，最后通过仿真和实验证明了这种方案的有效性。
2 有源共模电压消除器
概述
共模电压的定义公式为

当电机的定子绕组接三相对称电源时，（Vao+Vbo+Vco）为零，电机端不存在共模电压；当电机的定子绕组接三相两电平逆变器时，由于逆变器在任意给定时刻都有三个开关动作，组成8种开关状态，使逆变器输出电压（Vao+Vbo+Vco）的总和通常不为零，为±Vdc/2（所有上三个开关或下三个开关导通）或±Vdc/6（两上一下或两下一上开关导通）(Vdc为逆变器直流母线电压)。电机端共模电压非常高，而且随着逆变器的调制频率的增加和电机零序阻抗的降低，共模电压可以产生非常大的共模电流，产生电磁干扰（EMI）等问题，破坏系统或电机，因此需要抑制。
三相逆变器输出产生的共模电压是一个四电平电压，如图1所示。电压参考点为直流母线电压中性点。< 有源滤波器结构 为消除三相逆变器输出产生的共模电压，本文采用一个单相逆变器和一个五绕组共模变压器，其原理结构如图2所示。三相和单相逆变器由控制单元（DSP）控制。这种软件控制方法可以省掉硬件电路如共模电压检测电路等，简化单相逆变器的控制电路。五绕组共模变压器结构如图3所示。采用两个环型铁心，每一个铁心上套一个原绕组，匝数N1=3/2N；三个副绕组同时绕在两个铁心上，匝数均为N。两个原绕组中1b端和2a端相连且接到直流母线上两个电容C的中性点0上，1a端接到单相逆变器中IGBT7和8的中点c上，2b端接到IGBT9和10的中点d上，三个副绕组的a端接到三相逆变器的输出端上，b端接到电机的三相出线端上。由于单相逆变器中IGBT9、10桥臂工作时实际上是处于三电平的工作状态，在其输出点d与0点之间串入一电阻R，使IGBT9、10关断时，其输出点d电位迅速回落到0点电位。



由于流入感应电机的共模电流非常小（理论上为零），单相逆变器中的IGBT和二极管的额定电流非常小，其额定电压与逆变器中的IGBT相同。共模变压器的两个原绕组的额定电流也非常小，其副绕组由于要通过驱动系统的额定电流，要求绕组导线直径较大。共模变压器的铁心要用高频铁磁材料制作，由于PWM脉冲的频率非常高，故所需铁心的截面积不大。 控制原理：为消除三相逆变器输出的共模电压，必须要求本文提出的有源滤波器能够产生四电平的输出电压。为此，根据本文所提结构，单相逆变器的四个IGBT的控制规律如表1所示。表中ON表示该IGBT处于导通状态，OFF表示该IGBT处于关断状态。输出表示经五绕组共模变压器叠加到三相逆变器输出端的电压。输出计算举例：假设IGBT7和IGBT9导通，其它关断（第二种情况），这时，单相逆变器的c点和d点均输出+1/2Vdc，加到五绕组变压器的原边上。根据同名端和绕组的匝数比及绕组原边的接线，三个副绕组上均感应电压：（+1/2Vdc）-2/3%26acute;（+1/2Vdc）= +1/6Vdc。由于通过共模变压器叠加到三相逆变器输出端的电压与三相逆变器输出的共模电压反向，从而达到消除共模电压的目的。由于三相逆变器的输出相电压波形与其相应相的上桥臂IGBT的控制信号波形相同，仅幅值不同，而共模电压是逆变器输出相电压对参考地的三相和的1/3，因此逆变器输出的共模电压可以通过IGBT的控制信号计算出来。而单相逆变器又是根据共模电压进行工作的，单相逆变器的控制信号也可以根据三相逆变器的三个上桥臂IGBT的控制信号得出。因此用一个控制单元（DSP）即可实现三相逆变器和单相逆变器的控制工作。
图4为逆变器采用正弦波PWM（SPWM）控制时根据IGBT的控制信号计算出的任一个PWM脉冲周期的共模电压波形及单相逆变器的控制信号波形。图4(a)为三相参考正弦波Va，Vb，Vc及载波Rec波形；参考正弦波与载波相比较，得出PWM脉冲，图4(b)~(d)为三相逆变器中上三个桥臂中IGBT的控制信号，下三个桥臂控制信号与之相反；图4(e)为计算出的共模电压波形，可见，共模电压为四电平电压；图4(f)~(i)为单相逆变器中4个IGBT(7~10)的控制信号，其控制规则满足表1的要求。当将这4个控制信号与共模电压相比较，同时考虑共模变压器变比的作用，可以看出，其输出规律与共模电压完全相同。因此，这种结构的滤波器可以做到完全消除三相逆变器输出的共模电压。3 仿真分析 采用仿真软件为Matlab ，三相电源电压为380 V，50 Hz；二极管整流，直流母线电压为537 V；PWM-IGBT逆变器，载波频率为2 kHz；3 kW感应电机。电容C的值为5 mF，为防止由于实际电容在充放电过程中可能出现的电压不相等而导致参考点电位出现波动的情况，在电容C上又分别并联了一个10 kW的均压电阻。在仿真时未出现电压不相等的情况。
图5为采用图2所示结构进行仿真一个PWM周期的结果，由图5(a)可知除幅值不同外，其波形形状与计算出的图4(e)相同；通过图5(a)和(c)比较可以看出，加入本文提出的逆变器输出有源滤波器，可以将三相逆变器输出的共模电压幅值几乎完全降为零，从而消除了共模电压对感应电机产生的不良影响。图5(c)中的两个毛刺脉冲产生的原因是共模电压从-1/6Vdc向-1/2Vdc变化或+1/6Vdc向+1/2Vdc变化时，相应的要求单相逆变器中的IGBT9或10关断（IGBT7或8仍然导通），而实际上d点输出电位不能迅速回到0点电位，使滤波器输出电压小于三相逆变器的输出共模电压，从而产生了毛刺脉冲。可以通过改变电阻R的阻值达到降低毛刺脉冲幅值的目的。4 改进方案图2所提方案虽然可以很大程度的消除电机端的共模电压，但是从图5(a)中的波形可以明显看出，一个PWM周期中逆变器输出的共模电压有6次变化，而图5(c)中消除了共模电压的4次变化，还有2次变化虽然在幅值上基本消除了逆变器输出的共模电压，但是对共模电压的dV/dt沿无明显影响。为此，对图2进行改进，改进的目的是当共模电压从-1/6Vdc向-1/2Vdc变化或从+1/6Vdc向+1/2Vdc变化时，使d点电位迅速回落到0点电位。图6为改进后的滤波器结构。与图2相比，在电阻R的两端反向并联了两个IGBT（11和12）。当IGBT9关断而IGBT7继续导通时（即需要滤波器输出+1/2Vdc时），IGBT11导通，使d点和0点电位差迅速降至IGBT的导通压降，而IGBT的导通压降为2～3 V，远远小于1/2Vdc，可以近似为0，使滤波器输出的电压迅速达到了三相逆变器输出的共模电压，从而起到消除共模电压的目的。



图7为IGBT7~IGBT12的控制信号波形。IGBT11和IGBT12的控制规律为当IGBT7或IGBT8导通期间，如果IGBT9或IGBT10关断（即需要滤波器输出+1/2Vdc或-1/2Vdc）时，IGBT11或IGBT12导通，其它时间关断。图8为采用改进后的滤波器时三相逆变器输出的共模电压(a)，滤波器输出共模电压(b)和电机端共模电压波形(c)。比较图8(c)和图5(c)，可以看出，加入IGBT11和IGBT12以后，毛刺脉冲的幅值减小了3/4。
5 实验分析
实验时采用自行研制的变频器。整流桥采用FUJI 6R130G-120；直流母线电容为HGC 450V 3300 mF，逆变器采用IPM 智能功率模块，载波频率为

用于分布式在线UPS中的并联逆变器的一种无线控制器已经发送。

Control of Parallel Inverters in Distributed AC Power Systems with Consideration of Line Impedance Effect在分布式交流电力系统中考虑连线阻抗影响时的并联逆变器控制 论文发到你的邮箱了