A new concept and method of vibration reduction of a rolling piston-type compressor for a room air conditioner is proposed. To suppress the compressor vibration due to the excit of the torque, the torque control method using a microcomputer control which makes the motor output torque nearly equal to load torque variation by means of gas compression of the compressor at each angular position through one revolution is applied. Theoretical analysis and computer simulation show that the control method in which the rotational variation (fluctuation of speed or acceleration) for one revolution caused by the load torque and transmitted to the motor output torque at the next revolution due to the cyclic characteristic of the compressor load, that is to say, "repetitive control" can be adopted. Thus reduction of compressor vibration is possible.
