In the paper it makes focal points of the zig - zag transformer " influences on the harmonics of line side and pulse shifting control influence on the harmonic of motor side . the theoretical computation and computer simulation waveforms are presented 重点分析了变压器曲折接法和移相多重化整流对网侧谐波的影响及移相pwm控制方式对减少输出侧谐波的作用，并给出理论计算结果和计算机仿真波形。
