A Suppression Strategy for Subsequent Commutation Failures Considering Commutation Capability of Recovery Process

In order to suppress subsequent commutation failures of high voltage direct current (HVDC), the dynamic process of electrical and control quantities during system recovery is studied, and the main reason for subsequent commutation failures is proposed in the paper. During the recovery process, the voltage of the converter bus after the fault is in a state of drop, the actual firing angle of the inverter is in overshoot, and direct current continues to rise. These factors result in an insufficient system commutation capability to complete the transfer of valve arm inductance energy during the commutation process. A suppression strategy for subsequent commutation failure considering the commutation capability of the system recovery process is proposed. By limiting the direct current (DC) when the firing angle is in overshoot, the system commutation capability is increased, and subsequent commutation failures are suppressed. In addition, the DC system is effectively recovered. The proposed theory is tested and v