Error Sign Detection-Based Compensation of Commutation Error for Use in Sensorless Position Control of BLDCM

This article presents a novel commutation error closed-loop compensation method for the position sensorless brushless dc motor. A key challenge is addressed that the conventional closed-loop compensation method fails in the case of no available analog-to-digital converter (ADC). The proposed method consists of a commutation error sign detection circuit and a compensation algorithm. First, the voltage of the virtual neutral point with respect to dc-link midpoint is transformed to obtain a logic level. The logic level can indicate whether the commutation is advanced or delayed. Then, the logic level is mapped to a commutation error sign flag variable, based on which a novel iterative compensation algorithm is designed. Compared with the conventional method, the proposed method achieves a high-precision closed-loop compensation using only one general-purpose input/output of the digital processor instead of ADC. Finally, the experiments on a magnetically suspended control moment gyro prototype validate the effectiveness of the proposed method.

Automated summary

This article introduces a novel commutation error closed-loop compensation method for sensorless brushless DC motors, addressing the challenge of conventional methods failing without an available ADC. The method utilizes logic level transformation and an iterative compensation algorithm to achieve high-precision closed-loop compensation, using only a general-purpose input/output of the digital processor. Experimental validation on a magnetically suspended control moment gyro prototype confirms the effectiveness of the proposed method.