Vibration Suppression Method using Disturbance Observer in Sensorless 120-degree Conduction Compressor Motor Drive

A vibration suppression method is proposed for a compressor motor driven in the sensorless 120- degree conduction mode. The proposed method estimates motor speed and angle from the zero-crossing points of the back electromotive force (EMF) and suppresses vibration using a disturbance observer in conjunction with a Smith compensator. The experimental results demonstrate that the proposed method reduces the fundamental frequency component of vibration by 94.2% at a low speed of 900min-1 (0.19p.u.).