ELECTRICAL VALVE CIRCUIT APPARATUS

摘要

An electrical valve circuit apparatus which comprises an electrical valve circuit comprising a plurality of main control electrical valves operationally connected between a main DC circuit system and a main AC circuit system, at least one pair of commutating arms composed of at least two main control electrical valves for sequentially commutating the current, at least one arm of the group of commutating arms is an auxiliary DC circuit system, and an auxiliary electrical valve apparatus and an auxiliary power source connected in series to the auxiliary DC circuit system.