AC/DC CONVERTER

PURPOSE:To suppress fluctuation in the AC voltage or reactive power of a sound system by employing bypass operation for a converter connected on the faulty system and matching the control target current of a converter on the sound system with the reactive power consumed by the converter prior to failure of the system. CONSTITUTION:At first, a reactive power detector 51 detects the reactive power based on the current and voltage of a sound system detected through a current transformer 4 and a voltage transformer 5 and the reactive power thus detected is stored in a reactive power memory circuit 52. Upon occurrence of a failure on an AC system 11, a converter 13 on the failed system is subjected to bypass pair operation and a circuit 55 switches the control target 1d of a converter on the sound system from the output Idp of a control target current circuit 54 to the output Idp of a constant reactive power control circuit 53. The circuit 53 compares the output from the circuit 51 with a control target value, i.e., the output from the circuit 52, and produces an output Idp. This constitution can suppress fluctuation in the AC voltage or reactive power of a sound system.