Microcontroller Implementation of Lookup-Tablebased Hall Sensor Correction for Improving Dynamic Performance for Brushless DC Motors

Hall-sensor-controlled brushless DC (BLDC) motors are used in many applications due to their low cost, ease of control, and good torque/power characteristics. In an ideal case, the Hall sensors are spaced precisely 120 electrical degrees apart. However, in low-cost machines, there may be significant errors in the positioning of Hall sensors, leading to uneven conduction intervals and an increase in torque ripple. Previous research proposed averaging filters for balancing the Hall sensor signals and performance restoration. However, averaging filters also introduce a delay and may cause degradation of transient performance. This paper proposes a filtering approach combined with a lookup table (LUT) to remove the undesirable filter delay and improve performance during accelerations/decelerations. The proposed methodology is implemented on a microcontroller and demonstrated experimentally on a typical industrial BLDC motor, achieving significant improvement in transient performance over the previous methods.