MOTOR DRIVING DEVICE WITH INSULATION RESISTANCE DETECTION FUNCTION, AND MOTOR INSULATION RESISTANCE DETECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a motor driving device which allows measurement of an accurate motor insulation resistance value even at a high temperature without being affected by a leakage current of a semiconductor switching element.SOLUTION: The motor driving device of the present invention includes: a converter part; a power supply part; a plurality of inverter parts which convert DC to AC by upper arm switching elements connected between capacitors and motor coils and lower arm switching elements connected between the capacitors and the motor coils, to drive a plurality of motors; a second switch which connects the capacitors to the ground; a current detection unit which measures currents flowing between the capacitors and the ground; a voltage detection unit which measures voltages of the capacitors; and an insulation resistance detection unit which detects insulation resistance values of the plurality of motors by using current values and voltage values measured in a state where switching elements to which a motor coil being a measurement object is connected are turned on and switching elements to which motor coils being not the measurement objects are connected are turned on.