一种基于ZCT软开关的三相PWM逆变器技术

A Three-phase PWM Inverter Technology Based on ZCT Soft-switching

采用软开关技术可以有效地减小开关动作带来的损耗,但由于增加了辅助回路,又会造成额外的损耗。文章介绍了一种基于零电流转移(ZCT)软开关的三相光伏并网逆变器,分析了这种软开关技术的工作原理,并提出了一种软开关谐振参数的设计方法,从而使软开关的总损耗最小。同时对研制的100kVA软开关光伏并网逆变器样机进行了实验,并对软、硬开关的开关损耗进行了对比研究。

Soft-switching technology can effectively reduce the loss caused by switching, but with the addition of auxiliary circuit, will result in excess loss. This article describes a three-phase photovoltaic grid-connected inverter based on zero current transfer （ZCT） soft - switching, analyses the working principle of soft-switching technology, and proposes a design method of soft-switching resonant parameters, which can realize the lowest of total soft-switching loss. Meanwhile, the experimental results of the 100 kVA soft-switching photovoltaic gridconnected inverter prototype are given, and then the soft-switching and hard-switching losses are studied comparatively.