Hitachi Industrial Equipment Systems Co., Ltd.

Kouji Obata

Takeshi Obata

Tadahiro Shimozono

Koichiro Saito

Osamu Matsumoto

Keiji Fukushi

Apparatus and method for partial discharge detection of turn-to-turn insulation in motor has a surge generator for generating a surge voltage to the windings of the motor by applying a pulse voltage, and a partial discharge current detector for detecting partial discharge currents between the winding turns of the motor. The surge generator generates in and between the windings of the motor the surge voltage that has the rise time and fall time corresponding to the rise time of the surge voltage observed at the motor terminal when the motor is driven by an inverter, and that is repeated at a frequency of 50 Hz to 20 kHz.

Apparatus and method for detecting partial discharge at turn-to-turn insulation in motor

A frequency converter for outputting a power to drive a motor, having: an inverter unit for inverting a d.c. power to an a.c. power; a control unit for controlling the inverter unit; and a housing for supporting at least the inverter unit and control unit, wherein a rise time change unit is provided in the housing, the rise time change unit changes a rise time of a waveform of a voltage output from the inverter unit.

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Hitachi, Japan

Kouji Obata