COMPRESSOR-DRIVING DEVICE, COMPRESSOR PROVIDED WITH SAME, AND FREEZING CYCLE APPARATUS PROVIDED WITH COMPRESSOR-DRIVING DEVICE AND WITH COMPRESSOR

摘要

The present invention is provided with a control unit (23) for driving a compressor using PWM, an inverter circuit unit (4) for supplying electric power to an electric motor with which the compressor is provided, a drive circuit (5) for driving the inverter circuit unit (4) in accordance with control signals, a voltage-detection unit (9) for detecting voltage outputted to the electric motor, and an electric current-detecting unit (10) for detecting electric current outputted to the electric motor. When the product of the detection value of the voltage-detecting unit (9) and the detection value of the electric current-detecting unit (10) is greater than a predetermined comparative value, the duty ratio of the control signals is reduced, and the inputted electrical power that the inverter circuit unit (4) supplies to the electric motor is reduced to or below a predetermined inputted electrical power level.