FAULT-DETECTING PROTECTIVE DEVICE FOR RECTIFIER-TYPE CURRENT LIMITING DEVICE

PROBLEM TO BE SOLVED: To provide a rectifier-type current limiting device which separates a current which passes the rectifier-type current limiting device when a system fault occurs from a current which passes the rectifier-type current limiting device before the fault current becomes exces sive, and makes its resetting possible after tat, to solve the problem of being excessively bonded if removal of a fault of a circuit-breaker, etc., delays, when the fault current becomes excessive, since the current limiting effect of a DC reactor 4 lowers with the increase of duration of the fault. SOLUTION: A voltage detecting means 11 detects the voltage of bus-bars 1, 2 inside or in the vicinity of the rectifier-type current limiting device 10, and outputs voltage detection signals. A level determing means 12 judges whether the voltage detection signals detected by the voltage means 11 satisfy condition for a system side fault, and outputs a voltage-side fault signal. A current detecting means 13 detects current inside the limiting device 10, and outputs a current detection signal. A level determinating means 14 outputs a current side fault judgment signal, when it is judged that a system side fault condition is satisfied on the basis of the current detection signal. A switch opening command means 15 gives a switch open command to a switch 9, after the voltage side fault judgment signal and the current side fault determinating signal are inputted.