PARTIAL DISCHARGE MEASURING APPARATUS

PROBLEM TO BE SOLVED: To provide a partial discharge measuring apparatus capable of easily and reliably specifying an occurrence phase or an occurrence location of partial discharge of an inverter-driven motor. SOLUTION: Switching noise from an inverter device 2 is removed by a high-pass filter 7, connected to a feeder cable 4 connected to a power source terminal of the motor 3 that selects only the partial discharge signals generated by partial discharging in the motor in each phase. After a peak detection circuit 8 has detected a peak arrival time, at which the amplitude of selected partial discharge signals of each phase reaches its peak, the occurrence phase of partial discharging is determined, on the basis of the relation among peak arrival times of partial discharge signals of the phases at an arithmetic processing circuit 9. Then the differences among the peak arrival times of partial discharge signals are determined, with reference to the occurrence phase of partial discharging, and the occurrence location of partial discharge is specified, on the basis of the relation between the time differences and the transmission time of partial discharge signals for every coil of motor winding. COPYRIGHT: (C)2008,JPO&INPIT