The research of DC capacitance voltages balancing strategy based on cascade STATCOM using individual phase instantaneous current tracking

Due to the shunt loss, switching loss and pulse delay, the DC capacitors voltage of cascade STATCOM can´t maintain balanced which would influence the output voltage harmonics and even its normal operation. A novel DC capacitors voltage balancing control strategy based on individual phase instantaneous current tracking is proposed in this paper, the active power is properly distributed among the H-bridge units in the same phase to achieve the balance of DC capacitors voltage, and it is theoretically proved that the method is suitable for various condition while won´t change the fundamental component of output voltage. The correctness and effectiveness of the method are validated by MATLAB simulation.