Motor drive apparatus with function to detect abnormality in power device

A motor drive apparatus comprising:

• a converter configured to convert AC power supplied by an AC power source to DC power and to output the DC power to a DC link;
• an inverter including power devices provided for an upper arm and a lower arm, which power devices are ON/OFF controlled by respective gate voltages applied thereto, to convert the DC power in the DC link to AC power for driving a motor;
• a capacitor provided in the DC link;
• a shut-off circuit configured to open and close an electrical path between the AC power source and the converter;
• a constant current control unit configured to perform control in such a manner as to allow a constant current supplied by the capacitor charged with DC power to pass through a detection target power device among the power devices in the inverter;
• and
• an abnormality detection unit configured to detect an abnormality in the detection target power device based on changes in voltage between a collector and an emitter of the detection target power device during a period in which the constant current passes through the detection target power device.