Abstract:Abstract: The response behavior of UHVDC project under AC fault condition of inverter side are analyzed with consideration of commutation failure prediction. The impact of HVDC commutation failure prediction on electrical quantity of DC transmission terminal is discussed,and the sensitivity of the parameters in the predictive control of commutation failure is analyzed. The results show that the input of commutation failure prediction can really reduce the duration of commutation failure. Finally,after the commutation failure occurring in the voltage sag of inverter side,its influence on the recovery speed of active power and the stability of AC / DC system is analyzed.