Abstract: For cost reasons, the opplication of single cylinder rotor compressors almost cover all air conditioners below 1.5 P. Due to the structural structure and load characteristics, the traditional sensorless position presumption used in the internal PMSM motor drive control can't keep up with the pulsating load and there are shortcomings of detection error, leading to the speed and phase current ripple. Extracted the rotating ripple component containing the position error in the phase-locked loop control, and it is made to be 0 to correct the frequency conversion. In the speed loop control, the rotation pulsation component contained in the velocity feedback is removed, which greatly improves the precision of position detection, inhibits the fluctuation of speed and phase current, and improves the performance of the whole machine. The effectiveness of the control method is verified by simulation calculation and whole machine test.

Key words: Compressor, Sensorless position presumption, Position error, Phase-locked loop and velocity loop, Current ripple