Hitachi Industrial Equipment Systems Co., Ltd.

Shigetoshi Yagihara

Daisuke Matsumoto

Masahiro Hiraga

Fumihiro Sato

Naoki Takata

Keisuke Tanabe

With the aim of improving the reliability of a power conversion device for driving a motor, this power conversion device is provided with a rectifying portion for rectifying an AC voltage and outputting a DC voltage, a smoothing capacitor for smoothing the DC voltage, an inverter portion into which the DC voltage is input and which outputs AC power, an inverter drive portion for outputting a gate signal to the inverter portion, a regenerative braking portion connected in parallel with the smoothing capacitor, a regenerative braking drive portion for outputting a gate signal to the regenerative braking portion, a control portion for outputting drive signals to the inverter drive portion and the regenerative braking drive portion, a regenerative braking overcurrent detecting portion for outputting an overcurrent detection signal if the current flowing through the regenerative braking portion exceeds a determination value, and a latch portion into which the overcurrent detection signal output from the regenerative braking overcurrent detecting portion is input and which outputs a gate output interruption signal to the control portion, wherein switching elements of the inverter portion and the regenerative braking portion stop in an off state when the regenerative braking overcurrent detection portion detects an overcurrent.

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Tokyo, Japan

Shigetoshi Yagihara