Considering the wiring forms of converter transformers in the practical high voltage direct current(HVDC)systems

the impact mechanism of prediction control of commutation failure and initial fault angle on commutation failure is analyzed from the view of the commutation voltage-time integral area. The dominant factors that influence the commutation failure under the different severity circumstances of falults in alternating current(AC)system are analyzed. The computing method and procedure of initial fault angle range that results in commutation failure and the commutation failure probability considering the prediction control of commutation failure is proposed. It is pointed out that the prediction control of commutation failure intensifies the impact of initial fault angle on commutation failure. Simulations based on the typical monopole HVDC system using PSCAD/EMTDC software are done to verify the correctness of the theoretic analysis and the effectiveness of proposed computing methods.