Vibration Suppression Method Using Disturbance Observer in Sensorless 120-Degree Conduction Compressor Motor Drive

This paper proposes a vibration suppression method for a compressor motor driven in the sensorless 120-degree conduction mode. The proposed method estimates motor speed and angle by zero-crossing points of back 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 15 rps (0.19p.u.).