一种可抑制输入不平衡的五电平注入式电流源型整流器

三相输入电压不平衡现象严重影响了多脉波整流器的正常工作,使网侧电流引入大量低次谐波。五电平注入式电流源型整流器拓扑通过规律性地切换四组注入开关器件,改变了注入支路平波电感端电压的分布,进而抑制了输入电压不平衡对系统电流谐波的影响。首先,分析了五电平注入式电流型整流器的工作原理,通过比较3种注入电路脉冲组合序列,指出采用组内循环脉冲可以有效减小注入电感的纹波电流幅值;其次,研究了拓扑对三相输入电压不平衡的抑制机理,并从系统等效容量的角度研究了本拓扑的优势;最后,通过仿真与实验证明了分析的有效性。

A Novel Five-Level Reinjection Current Source Rectifier under Input Voltage Unbalance

The imbalance among the three-phase input voltages always affects the normal operating conditions of the multi-level rectifiers and introduces lots of low-order current harmonics to the line side.The five-level reinjection current source rectifier changes the voltages across the flat-wave inductances and suppresses the influence of the voltage unbalance on the system currents through switching the four groups of the reinjection switches regularly.In this paper,the configuration and operation of the five-level reinjection current source rectifier are analyzed first.At the same time,it's pointed out that the circulation reinjection pulses could reduce the current ripple of reinjection inductance effectively by comparing three different reinjection firing pulses.Secondly,the mechanism analysis of the inhibiting effect on the input voltage unbalance is given and the advantage of the equivalent capacity of the system is proved.At last,the simulation and experimental results demonstrate the availability of the above analysis.