Research on DC Power Control Strategy for Mitigating the Continuous Commutation Failure

The method for suppressing the continuous commutation failure is a vital issue of AC/DC hybrid power systems. However, most of existing literature focus on DC control system and even the converter topology, which is not able to meet the needs of control strategy for actual systems at this stage. Therefore, a DC power control strategy to cope with the continuous commutation failure is proposed in this paper. Firstly, the reactive interaction characteristic of AC/DC system and the main cause of continuous commutation failure are analyzed, and a method for evaluating risk of continuous commutation failure based on critical voltage is proposed. Then DC power is reduced or restored in real time in order to improve the reactive power recovery characteristic of the DC system. Finally, the proposed strategy is verified by simulation based on the actual system. The result shows that the strategy can effectively mitigate the continuous commutation failure, and has fine engineering adaptability and application prospect.