Development of Hall Sensor Fault Compensation Method to Improve Control Reliability of BLDC Motor

In this study, we develop an improved all-pass filter that compensates the signal of a faulty Hall sensor using two Hall sensors that operate normally when a Hall sensor fault occurs in a permanent magnet synchronous motor operating at high speed. A fault in the Hall sensor is the cause of the reliability degradation of the system. To compensate the signal of the faulty Hall sensor, two signals of the Hall sensor that operates normally are applied to the improved all-pass filter to compensate the signal of the faulty Hall sensor by delaying the phase. Unlike the method of switching to sensorless control, the compensated method using the improved all-pass filter has a higher reliability than the sensorless control method because it is compensated using the normal operating Hall sensor. The output signal phase delay and duty nonlinearity according to the input frequency change of the original all-p ass filter are linearly improved by IC chips such as decoder, And-gate, and D Flip-Flop. Finally, the designed circuit is analyzed through simulation and experiment to verify the results of this study.