适用于大功率逆变器的预充电方案研究

Research on the Pre-charging Method Suitable for High-power Inverters

在交直交逆变器的启动过程中,预充电是十分重要的环节。传统的预充电电路应用较广,但成本随着逆变器功率的增大而增加,并且启动电流较大。设计了三相桥式半控整流预充电电路。通过调节晶闸管触发角的方式进行预充电,既降低了成本,又可以灵活控制母线电压,减小了启动时电容的充电电流。并通过MATLAB仿真对比了两种预充电电路的启动特性。

Pre-charging is a very important process during the start-up period of the AC-DC-AC inverter. Despite of its wide application,the traditional pre-charging circuit has its cost going up with increasing inverter power. In addition,it has a high starting current. A precharging circuit is designed by using a three-phase half-controlled bridge rectifier. Pre-charging realized through the adjustment of the trigger angle of the thyristor can not only reduce the cost,but also control the bus voltage,thus reducing the charging current of capacitor at the time of start. Furthermore,The starting characteristics of the two circuits are compared through MATLAB simulation.