Abstract: When the variable frequency compressor starts, due to the inertia of the movement, the compressor exists hysteresis and overshoot, which results in obvious noise fluctuation. In addition, the refrigeration system has a large load at the stage of start-up, the change of speed is easy to cause the abnormal noise and poor user experience. By studying the influencing factors of movement rotation inertia, on the premise of ensuring the normal start of variable frequency compressor, an optimized start-up control method of variable frequency compressor is proposed to control the instantaneous noise fluctuation within 2 dB(A). Improve the sound quality of refrigerators and freezers.

Key words: Variable frequency compressor, Hysteresis, Overshoot, Moment of inertia, Start-up, Noise fluctuation