Improved Extinction Angle Control for Subsequent Commutation Failure Mitigation in LCC-HVDC

Extinction angle control is one of the main control strategies to mitigate the commutation failure in HVDC, but the problem of insufficient response speed and control precision still can't be solved effectively based on the current research on measured and predictive extinction angle control. Thus, an improved extinction angle control method to mitigate subsequent commutation failure is proposed. Firstly, the influence of voltage harmonics on the commutation process of HVDC system is analyzed, and the prediction method of extinction angle considering the voltage harmonics is proposed. Then, the predictive value of the subsequent commutation process is introduced into the original control logic of the system to improve extinction angle control. Finally, the proposed control method is simulated and verified based on the standard test system. The simulation results show that the method can improve the response speed and control precision of the extinction angle control to a certain extent, and thus can effectively mitigate the subsequent commutation failure in HVDC.