链式静止同步补偿器子模块电压均衡控制

Control Strategy Research on Sub-module DC Voltage Balance for Star-connected Cascaded STATCOM

链式静止同步补偿器(STATCOM)在实际运行中,解决级联H桥功率模块的电容电压平衡是装置安全可靠运行的关键问题。首先对链式STATCOM的基本模型进行分析,阐述其工作的基本原理;然后以补偿H桥功率单元的有功损耗为出发点,通过引入交流平衡因子,提出了一种新型的分离直流母线电容电压均衡控制策略,其无需额外的辅助电路、具有良好的动、稳态性能,并且实现简单。同时,分析了该均压控制策略对系统运行特性的影响。最后,搭建链式STATCOM实验平台,验证了该均压控制策略的有效性。

In the actual operation of cascade static synchronous compensator(STATCOM),solving the capacitance voltage balance of the cascade H-bridge power module is a key issue for the STATCOM device.The basic model of the cascade STATCOM is analyzed,and the basic principles of its work are elaborated in the first.Then,to compensate the active loss of H-bridge power unit as the starting point,a new type of separate DC capacitance voltage balancing control strategy is proposed with AC balance factor introduced.It does not require additional auxiliary circuitry, and has good dynamic and steady state performance,and also is simple implemented.At the same time,the characteristics of the system under this balancing control strategy are analyzed.Finally, a cascaded STATCOM experimental platform is built,and the effectiveness of the control strategy is verified.