Method for analyzing influence of alternating current system fault on commutation failure probability of each direct current commutation valve

The invention discloses a method for analyzing the influence of an alternating current system fault on the commutation failure probability of each direct current commutation valve, and belongs to the technical field of extra-high voltage direct current transmission line protection and control. According to the technical scheme, the method for analyzing the influence of the alternating-current system fault on the commutation failure probability of each direct-current commutation valve comprises the following steps: 10) analyzing a commutation failure mechanism; 20) analyzing the influence of the alternating-current side grounding fault on the commutation failure of each commutation valve, including the influence generated by single-phase short-circuit grounding analysis, two-phase short-circuit analysis and two-phase short-circuit grounding analysis; and 30) establishing a reasonable simulation model, comparing the reasonable simulation model with the inference of the alternating-current side grounding fault a