三电平逆变器窄脉冲补偿方法研究  

Study of narrow pulse width compensation technique for three-level inverters

作　　者：薄保中[1] 刘卫国[1] 罗兵[1] 苏彦民[2] 

机构地区：[1]西北工业大学自动控制系,陕西西安710072 [2]西安交通大学电气工程学院,陕西西安710049

出　　处：《电力自动化设备》2004年第8期25-28,共4页Electric Power Automation Equipment

基　　金：国家863计划资助(2002AA755023)

摘　　要：二极管箝位三电平逆变器在中压大功率场合应用很广泛,采用可关断晶闸管GTO(GateTurn鄄offThyristor)或集成门极换向晶闸管IGCT(IntegratedGateCommutatedThyristor)时存在窄脉冲NPW(NarrowPulseWidth)问题。窄脉冲问题与中点电位波动问题相互交织在一起,目前的算法还没有非常成功地在一种PWM方法中解决好这两个问题的方法,SVPWM方法也都无法扩展到三电平以上。基于三电平SPWM方法,提出了零序电压注入ZSVI(Zero鄄SequenceVoltageInjection)窄脉冲补偿方法,零序电压注入即在三相参考电压中注入零序电压分量。仿真结果表明,采用ZSVI方法输出电压总谐波畸变率THD(TotalHarmonicDistortion)大大减小,输出电压THD不再受增加最大、最小窄脉冲宽度影响。因此可以通过增加最大、最小窄脉冲宽度提高系统的可靠性,而不影响系统的性能。提出的ZSVI方法可以推广到任意电平的逆变器的控制。Three-level diode-clamped inverter is widely applied in medium voltage high power drives. The NPW(Narrow Pulse Width) problem occurs when using GTO(Gate Turn-Off thyristor) or IGCT(Integrated Gate Commutated Thyristor),which is interweaved with neutral-point potential fluc-tuation. Up to now,there is no comprehensive method that can deal with these two problems in one PWM technique,and the SVPWM techniques can not be extended to three-level inverters either. Based on Sinusoidal PWM technique,ZSVI(Zero-Sequence Voltage Injection) technique is proposed as NPW compensation,in which zero-sequence voltage components are injected into three phase reference voltages. Simulation results show that,the THD(Total Harmonic Distortion) of output voltage can be greatly reduced by using ZSVI,and it is no longer affected by increasing minimum turn-on pulse width and turn-off pulse width. System reliability can thus be enhanced by increasing minimum turn-on pulse width and turn-off pulse width,without decreasing system specifications. The proposed ZSVI technique can be extended to any kinds of multi-level inverters. The project is supported by National High Technology Research and Development Program(863 Program)(2002AA755023).

关 键 词：三电平逆变器 窄脉冲 零序电压注入 

分 类 号：TN784.1[电子电信—电路与系统] TM92[电气工程—电力电子与电力传动]