When a thyristor valve works in inverting mode

strict conditions are required for the AC and DC systems connecting with the valve

and for the state of the valve itself. When phase change failure happens in the inverting side

the valve will endure larger current stress

also frequency fluctuation of the AC system and current surge at DC side will occur. Commutation failure phenomenon has occurred many times in the debugging process of South Korea Jeju HVDC transmission project.This paper from the commutation failure theory

through comprehensive analysis of field test results and simulation of fault phenomena simulation methods

determine the fault point and effectively solve the commutation failure problem

satisfy the engineering operational requirements.