Novel configuration of star-connected cascaded H-bridge STATCOM and its clustered voltage balancing strategy

This paper propose a novel configuration of star-connected cascade STATCOM with neutral line and corresponding structure of grid transformer. The proposed configuration are designed especially for industrial manufactory with 35kV grid voltage. On basis of this, this paper further put forward its control strategy of clustered voltage balancing based on zero-sequence current injection. The voltages of three clusters are firstly detected. Then the power flow need injecting of each phase are calculated through PI controller, and the relative zero-sequence current are derived according to the power flow reference. The proposed configuration and its clustered voltage balancing strategy will bring no negative or zero sequence current to 35kV grid. The simulation results verify the effectiveness of the proposed configuration and its control strategy.