Improved Sensor Control Method for BLDC Motors

Abstract

The article proposes the replacement of the classic control method of systems with BLDC motor sensors to a system where the inverter switching points are determined by means of a switching estimation algorithm. The switching points are calculated by a microcontroller in accordance with the Hall sensors' switching signals, but can be tuned using an external optimization algorithm. This method of controlling a BLDC motor allows us to use a correction algorithm that significantly improves the commutation of BLDC drives with unbalanced Hall sensors. Both the computation of the sensor's misalignment and the proposed method of correction were developed by the author to improve the functionality of drive systems with BLDC motors with closed-loop speed control. The use of this technique yielded very good results in both static and dynamic states. In addition, it made it possible to precisely influence the motor's commutation angle, which can minimise the production costs of such machines by foregoing the need to provide mechanical elements to move the sensors relative to the rotor axis. The article presents the results of work carried out on a laboratory bench built for this purpose.

Keywords

• BLDC motor
• sensor misalignment
• torque ripple