三电平高压大容量变频器中的短时间尺度脉冲现象

大容量变频调速系统中存在相当多的短时间尺度过渡过程，如电力电子器件的开关过程、换流回路的转换等，其作用时间一般在微秒至纳秒级。这些过渡过程将直接影响到电力电子装置运行的可靠性，因此，抛开传统的稳态研究模式，从脉冲的短时间尺度来看待这些过渡过程非常必要。该文以三电平高压大容量变频调速系统为试验平台，在得到大容量变频调速系统中各类波过程数学函数的同时，着力将PWM脉冲进行系统分类，综合考虑各类脉冲产生的原因及其作用效果，分析了最小脉宽对于系统动态和稳态性能的影响。试验结果验证了以上分析的正确性。

Short-timescale Pulse Phenomena in Three-level High Voltage and High Power Inverter

Various short-timescale transient processes exist in the High Power Adjustable Speed Drive(ASD)Systems,such as the switching transition of power semiconductors,commutating process and drive signal transmission,whose timescales ale generally from nanosecond to microsecond.These transient processes directly influence the reliability of powcr devices.Therefore it is necessary to investigate these short-timescale processes and penetrate their in-depth mechanisms instead of conventional steady.state research.Onthe high voltage and high power three-level ASD systems,the paper depicts the mathematical functions of various wave propagations.classifies the PWM pulses,summarizes their causes and effects and analyzes the effect of minimum pulse width on the dynamic and steady operations,as is difierent from the traditional literatures.Experiment validates the correctionoftheaboveanalysis.