A Calculation Method of Pseudo Extinction Angle for Commutation Failure Mitigation in HVDC

This letter presents a novel pseudo extinction angle (PEA) for the HVDC inverter, as well as its calculation method. The proposed PEA extends the measured extinction angle (EA) into a real-time calculated value. As a result, the non-measurability of the EA between two adjacent EA updating times, which is likely to cause commutation failures (CFs), can be avoided effectively. Simulation results verify the validity of the proposed PEA calculation method and prove the capability of the PEA to mitigate the CFs.