PROTECTIVE CIRCUIT FOR DIRECT CURRENT OVERVOLTAGE OF INVERTER

摘要

PURPOSE:To prevent the breakdown of parts due to the energy of reverse currents by a method wherein the overvoltage detecting circuit is mounted which detects voltage at the both ends of a smoothing capacitor, and an operating circuit for operating an interrupter by the output. CONSTITUTION:The overvoltage is detected by means of the overvoltage detecting circuit 13 through a voltage converter 7 at the both terminals of the smoothing capacitor 6 of the inverter, to whose DC input side the smoothing capacitor 6 is mounted and to whose AC output side the interrupter 2 is installed, an operating circuit 14 is worked by the detecting signals, and the interrupter 2 is interrupted and a circuit breaker 3 is tripped. Thus, since the overvoltage is detected in integral operation, voltage does not change rapidly, overvoltage can stably be detected, and the breakdown of parts due to reverse currents generated by the abnormality, etc. of an inverter gate control circuit in case of two parallel redundant operation of inverters can effectively be prevented.