应用于NPC型逆变器的三电平不连续PWM方法

Discontinuous PWM strategy considering neutral-point potential balance for a three-level NPC inverter

摘要: 针对低频大功率二极管中点钳位(NPC)型逆变器控制系统的不连续空间矢量脉宽调制原理及控制策略的研究,提出三电平不连续空间矢量脉宽调制方法,相比于传统三电平空间矢量脉宽调制方法,在相同的开关频率下,此方法可以显著降低逆变器的开关损耗.同时,文中对三电平逆变器的中点电压不平衡问题以及在现场应用中可能出现的PN电平跳变问题进行分析,并提出解决方法.最后,针对本文提出的调制方法做中点电压的平衡控制,给出对于该算法基于仿真和实验的验证.

Abstract: A novel discontinuous space-vector pulse width modulation(DSVPWM) strategy is proposed for a three-level neutralpoint-clamped(NPC) voltage source inverter. Compared with traditional space-vector pulse width modulation(SVPWM),the proposed strategy can largely reduce the switching losses of the inverter at the same switching frequency. Then,solutions to the imbalance of neutral-point voltage and the PN voltage jumps during application are proposed in this paper. At last,the three-level DSVPWM strategy is verified by simulation and experiment.