三电平SPWM波的改进算法研究与谐波分析

Research of Improving the Algorithm of Three-Level SPWM Wave and Harmonic Analysis

以提高正弦波脉宽调制(SPWM)供电质量为主要目的,SPWM脉宽调制法通常可分为两电平、三电平和多电平调制法,其中,三电平SPWM波比两电平SPWM波有更好的消除谐波特性。并且基于三电平的SPWM规则采样法是一种为简化SPWM波开关点计算衍生出来的计算方法,一定程度上可以替代比较调制算法。本文提出了一种三电平SPWM波开关点实时计算的方法,并且给出一般性计算公式。通过MATLAB编程,对计算结果进行了谐波分析,同时为了与实际应用相结合,提出了一种包含死区时间的三电平SPWM规则采样算法。在设计开关点算法时,把死区时间计算在内,分析了谐波含量,为工程应用作了铺垫。

To improve the sinusoidal pulse-width modulation （SPWM） power supply quality of the primary purpose of SPWM pulse width modulation can generally be divided into two-level, three-level and multi-level modulation, among them, the threelevel SPWM wave has the better harmonic cancellation characteristic than tow-level SPWM wave. Based on the three-level regular sampling of SPWM is a simplified calculation of SPWM wave switching points derived from the calculation, to some extent, it may substitute the method of modulation algorithm. This paper provides a three-level SPWM wave switch-point real-time calculation and gives a general formula. Then analyze the harmonic of this method by MATLAB, at the same time with a combination of practical application, a dead time included in the three-level SPWM regular sampling algorithm. When design switch-point algorithm, which contained the dead-time computation, then analyze the content of harmonic, which were paving the way for engineering applications.