A Commutation Error Compensation Method for Sensorless High-Speed Brushless DC Motor Drives Considering Nonideal Back-EMF

This paper proposes a new commutation error compensation method considering nonideal back electromotive force (EMF) for high-speed brushless DC motor (BLDCM) fed by quasi-current source inverter (QCSI). In different conduction modes of the motor, an auxiliary function unaffected by the voltage drop of resistors and inductors is first constructed. Then, the relationship between the difference of the auxiliary function integrals before and after the commutation and the commutation error angle is analyzed. According to this relationship, a commutation compensation angle regulator is designed. The proposed method can effectively compensate the commutation error under different working conditions without being affected by the change of motor parameters. Finally, the correctness of the theory and the feasibility of the method are verified.