A Commutation Error Correction Method For High-speed Brushless Dc Motor Based on the Phase Current

In brushless dc motor (BLDCM), precise commutation point and commutation interval, which impact motor torque ripple and motor efficiency are significant issue. Especially for high-speed high-power BLDCM drive without rotor position sensors (i.e. sensorless drive), the impact of commutation electrical angle error becomes more important. However commutation error is inevitable due to interference, detection error, motor parameters change, and correction of commutation error is difficult in very shortly commutation interval. In this paper, a novel current control strategy for the middle speed and high speed range is presented. A phase current closed-loop control and optimized current hysteresis controller based on adjacent half conduction period of phase current is adopted to autocorrect commutation electrical angle error. The proposed method has the characteristics of simple and rapid applying for high-speed BLDCM. Lastly, the feasibility and effectiveness of the proposed method is proven by experimental results.