Line voltage difference integral method of commutation error adjustment for sensorless brushless DC motor

Abstract

Sensorless Brushless DC Motor (BLDCM) often suffers from the inaccurate commutation signal, which degrades the operation performance inevitably. The inaccurate commutation signal will increase the loss of motor and torque ripple. In order to achieve accurate commutation, this paper presents a novel commutation error compensation method for sensorless BLDCM. With this method, the voltage integral value of the line voltage difference during the 60-degree conduction period is used to adjust the commutation instants, which avoids the negative effects owing to the parameter variation and elevates the robustness of system from external disturbances. Compare with conventional commutation correction methods, reconstruction of the virtual neutral voltage is not required, which reduces the corresponding complexity of the hardware circuit design. In addition, the integral intervals are determined by commutation signals, which simplify the detection of the integral boundary. The experiment and simulation results verify the feasibility and effectiveness of the proposed method.