零序电压注入的电力电子变压器电压平衡控制

capacitor voltage balancing problem exists in cascaded H-bridge converter-based power electronic transformer, it\'s more serious when the line voltages and output loads are asymmetric. A new cluster voltage balancing control with a zero-sequence voltage injection is proposed in this paper. A hypothesized phase is intentionally introduced by shifting the original zero-sequence voltage by 90 , so the zero-sequence can be represented by DC form. The relationship between the active power and the zero-sequence voltage is established, the zero-sequence voltage is calculated in the dq frame, and the trigonometric function is not involved, so the calculation is simple. As for the individual voltage balancing control, it achieves by trimming the duty cycle of d axis. The effectiveness of the proposed control strategy is verified by simulation results.