The single piston rotary compressor with PM synchronous motor is generally applied to air-conditioners due to its high efficiency and low cost. The single piston rotary compressor is, however, suffered by low speed operation due to its large mechanica...
The single piston rotary compressor with PM synchronous motor is generally applied to air-conditioners due to its high efficiency and low cost. The single piston rotary compressor is, however, suffered by low speed operation due to its large mechanical vibration at low speeds, whereas the low speed operation of the compressor is highly required for high efficient operation in air-conditioner. The mechanical vibration of the single piston rotary compressor is caused by large pulsating torque during one mechanical rotation of the piston. In this paper, the torque control with compensating pulsating load torque is presented. The load torque is estimated by the load torque observer and corresponding currents for pulsating load torque are compensated to the current reference. The simulation results show that the proposed algorithm reduces the speed ripples of a PM synchronous motor at low speeds.