Patent ID: 8232753

Claim:
A control device for an electric motor drive apparatus that controls an electric motor drive apparatus having an inverter converting a direct-current voltage into alternating-current voltages and supplying the alternating-current voltages to an alternating-current electric motor, and controls the alternating-current electric motor by current feedback, the control device for an electric motor drive apparatus comprising: a voltage control unit performing voltage control processing that determines alternating-current voltage command values serving as command values of the alternating-current voltages to be supplied to the alternating-current electric motor and generates switching control signals for the inverter; and a control mode selection unit selecting a synchronous control mode in which a cycle of electric angle of the alternating-current electric motor is synchronized with a switching cycle of the inverter, or an asynchronous control mode in which the cycles are not synchronized with each other, wherein current detection processing is performed to detect currents flowing in coils of the alternating-current electric motor in every standard calculation cycle that is set to a half of a cycle of the carrier, the voltage control processing is performed in a cycle of N times (where N is an integer of two or more) longer than the standard calculation cycle, and the voltage control processing is performed once by feeding back the current detection values for N times detected by repeating the current detection processing N times, if the synchronous control mode is selected.