| 摘要 |
In order to be able to comply itself to the environment-conscious design standard, a refrigerant heating method is obtained with high efficiency during standby and reduction of vibrations and noises of a bearing in a compressor. A compressor, a motor to drive the compressor, an inverter to apply a desired voltage to the motor, an inverter control means to control the inverter, and a bus voltage detecting means to detect a bus voltage of the inverter are provided, in which the inverter control means includes dormant refrigerant detecting means to detect a dormant state of refrigerant in the compressor, high-frequency AC voltage generating means to output a high-frequency AC voltage command out of a range of an operating frequency when the motor is undergoing compression operation to a coil of the motor on the basis of an output of the dormant refrigerant detecting means, an amplitude, and a phase, and PWM signal generating means to cause the inverter to generate a high-frequency AC voltage by generating a PWM signal on the basis of the output of the high-frequency AC voltage generating means and the output of the bus voltage detecting means. |
