Abstract: A boosting operation of a converter and the intermittent energization operation of an inverter are optimally performed in accordant with input or output. The power converter includes the converter capable of boosting a DC voltage outputted by switching operation alternately performing shorting and rectification; the inverter; an inverter capable of performing intermittent energization in which switching around zero cross of a motor current is turned off upon converting the DC voltage outputted by the converter into three-phase AC power; and a controller that controls the converter to perform boosting operation and the inverter to perform the boosting operation of the converter and the intermittent energization operation of the inverter linkingly.

Abstract: An air conditioner is provided that reduces user discomfort due to vibrations and noises at a compressor, piping, and the like such as of an air conditioner. To achieve this, an air conditioner includes: a compressor (10) that has a motor (12) and a compression mechanism (14) driven by the motor (12); a speed detector (43) that detects a rotation speed of the motor (12); a drive mode controller (48) that controls a drive mode of the motor (12); and refrigerant piping that is connected to the compression mechanism (14) and allows a refrigerant to flow therethrough, wherein the drive mode controller (48), for stopping the motor (12), decelerates the motor (12) to a rotation speed equal to or lower than a resonance frequency between the compression mechanism (14) and the refrigerant piping.

Abstract: An air conditioner is provided that reduces user discomfort due to vibrations and noises at a compressor, piping, and the like such as of an air conditioner. To achieve this, an air conditioner includes: a compressor (10) that has a motor (12) and a compression mechanism (14) driven by the motor (12); a speed detector (43) that detects a rotation speed of the motor (12); a drive mode controller (48) that controls a drive mode of the motor (12); and refrigerant piping that is connected to the compression mechanism (14) and allows a refrigerant to flow therethrough, wherein the drive mode controller (48), for stopping the motor (12), decelerates the motor (12) to a rotation speed equal to or lower than a resonance frequency between the compression mechanism (14) and the refrigerant piping.

Abstract: A boosting operation of a converter and the intermittent energization operation of an inverter are optimally performed in accordant with input or output. The power converter includes the converter capable of boosting a DC voltage outputted by switching operation alternately performing shorting and rectification; the inverter; an inverter capable of performing intermittent energization in which switching around zero cross of a motor current is turned off upon converting the DC voltage outputted by the converter into three-phase AC power; and a controller that controls the converter to perform boosting operation and the inverter to perform the boosting operation of the converter and the intermittent energization operation of the inverter linkingly.