级联H桥型STATCOM直流电压平衡策略研究

Research on DC Voltage Balance Strategy of Cascade H-bridge Type STATCOM

系统补偿电流的增大,会加剧级联H桥型STATCOM各链节间电压不平衡,造成系统整体性能下降。针对这个问题提出一种两级控制的方法,前级通过调节有功实现各链节间电压平衡,后级通过双环控制实现各相总电压的稳定。并在matlab中搭建仿真模型,仿真结果表明,提出的方法能很好地控制链节间直流电压平衡,使STATCOM具有更好的补偿性能。

The increase of the system of compensation current will exacerbate cascaded H-bridge STATCOM chain node voltage imbalance,resulting in decreased overall performance of the system.To solve this problem,this paper proposes a method of two-level control,the former stage by regulating the active power to achieve the chain of the voltage balance of each chain,after the implementation of the stability of the total voltage of each phase through a double loop control.The simulation model is set up in MATLAB.The simulation results show that the proposed method can control the DC voltage balance of the chain,and the STATCOM has better compensation performance.