Power conversion device and drive device

Abstract

A power conversion device that converts direct current to three-phase alternating current and outputs the three-phase alternating current comprises: an AC current sensor that detects two-phase current values ​​under three-phase alternating currents generated by the three-phase alternating current; a target current calculation unit that calculates a target current based on a target torque; a voltage command calculation unit that calculates a voltage command value based on the target current and a detection value from the AC current sensor; and an AC current sensor diagnostic unit that determines an anomaly of the AC current sensor based on a detection value from the AC current sensor.The AC sensor diagnostic unit comprises: a first diagnostic unit that determines the anomaly based on a two-phase voltage command value obtained by converting the voltage command value into a value in a two-phase orthogonal coordinate system with any output phase as a reference; and a second diagnostic unit that determines the anomaly based on a two-phase current sensing value obtained by converting a sensing value from the AC sensor into a value in the two-phase orthogonal coordinate system. The AC sensor diagnostic unit switches the determination between anomaly determination by the first diagnostic unit and anomaly determination by the second diagnostic unit according to an operating state of the power conversion device.

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