Adaptive commutation error compensation strategy based on a flux linkage function for sensorless brushless DC motor drives in a wide speed range

This paper presents a novel adaptive commutation error compensation strategy for the sensorless brushless DC (BLDC) motor based on the flux linkage function. It addresses the two key challenge problems on the sensorless control of the BLDC motor. The one is presenting a novel detection method for the BLDC motor rotor position signal to filter out the interference and the noise by the high frequency. The other one is proposing a commutation error compensation strategy to improve the system efficiency. In traditional sensorless control strategy, a deep low-pass filter is usually used to obtain the BLDC motor rotor position signal from the high-frequency interference. However, the delayed angle caused by the low-pass filter may be more than 90 electrical degrees in the high speed range. Therefore, a novel sensorless control strategy based on the speed-independent flux linkage function was proposed in this paper. The interference of the diode freewheeling was filtered by the software filter, and a closed-loop compensation algorithm based on the deviation of line-to-line voltages was illustrated to correct the commutation error in the high speed range. The stability and accuracy of the method was confirmed by a series of experiments.