| 摘要 |
PROBLEM TO BE SOLVED: To provide a control method for a compressor which can reduce a switching loss and a harmonic current in a PWM drive state. SOLUTION: An AC power supply voltage is rectified into a DC voltage by a rectifying unit, the DC voltage is transformed into a prescribed DC voltage and supplied to an inverter by an active filter, and the prescribed DC voltage is converted into an arbitrary AC voltage and applied to a motor of a compressor by the inverter to drive the motor. To this end, the switching means of the active filter is driven in a prescribed manner, so as to make an input AC current waveform (ref. Fig. 1 (a)) sinusoidal, while PWM control and PAM control are carried out to drive the motor. In the PWM drive state of the motor, the set value of the output DC voltage of the active filter is set lower than the value obtained by multiplying the voltage of the AC power supply by √2, or lower than that value by a prescribed value, to stop at least the switching means at the peak value part of the input AC current waveform (ref. Fig. 1 (b)). |
