H-bridge cascaded static var compensator（STATCOM）has many advantages

such as high voltage level

large equipment capacity

high equivalent switching frequency. But it is difficult to control phase voltage and capacitor voltage of each module of DC side

and this is an important reason for stopping to exert operating performance. So decentralized control strategy is proposed

and it is applied to the H-bridge cascaded static var compensator. This control strategy uses hardware architecture of combining PC with lower machine. PC control double-loop of voltage and current of AC side and lower machine achieves the balance control of capacitor voltage of each module of DC side. Results of simulation and experiment verify the effectiveness of the control strategy.