Self-Compensation of Commutation Phase Error for Brushless DC Motor

Abstract

BLDC motors are synchronous motors powered by DC electricity via an inverter which produces an AC electric current to drive each phase of the motor via a closed loop controller. Electronic commutation is the on-and-off of the semiconductor switches at appropriate time to turn stator windings. Commutation phase ripple is generated due to the different exchange rate between outgoing phase current and incoming phase current of inverter during commutation period. The self-compensation of commutation phase error is determined with analysis of the relationship between sampled current difference and commutation point phase shift, which is based on actual back EMF waveform. The study is conducted under exact, advance, and delayed commutation respectively. This method estimates the commutation time error by sampling the dc-link current in real time. By comparing the stable value of dc link current with incoming dc link current of inverter is identified the type of commutation, as exact, advance or delayed commutation.Fast convergence speed can be achieved by using this method.The simulation results using MATLAB/SIMULINK shows the model performance is satisfactory.

Keywords: Brushless DC motor, commutation phase error, Self compensation of commutation angle. 

Cite this Article

Raji K.K., Binoj Kumar A.C. Self-Compensation of Commutation Phase Error for Brushless DC Motor. Trends in Electrical Engineering. 2018; 8(3): 72–81p.