A configuration and control method of cascade H-bridge STATCOM

This paper shows a configuration and control method of cascade H-bridge STATCOM in three phase power system. The phase cluster of STATCOM consists of three H-bridge cells connected in series. The feature is that each H-bridge cell generates a different output voltage Vc, 2Vc, 4Vc. By this configuration, each phase cluster can generate 17-level output voltage. But, as well as the other cascade H-bridge multilevel converter, every H-bridge cell has isolated DC capacitor, and balancing problem of capacitor voltages exists. In this paper, a technique to balance the capacitor voltage of the cascade H-bridge STATCOM is proposed. Simulation results show the validity of proposed method.