Recovery Trajectory Tracking Control to Mitigate Consecutive Commutation Failures in LCC-HVDC

Commutation failures in LCC-HVDC transmission systems, especially at the inverter side, can be mitigated through effective control strategies. To address consecutive commutation failures caused by overshooting in traditional PI controllers, a closed-loop control strategy based on recovery trajectory tracking is proposed. This strategy utilizes feedforward control to generate real-time advanced firing angles based on the desired extinction angle trajectory, alongside feedback compensation control for extinction angle errors. Simulations conducted in PSCAD/EMTDC using the CIGRE HVDC benchmark system demonstrate that the proposed strategy effectively mitigates consecutive commutation failures under varying fault levels, enhancing system response.