Improved Advance-phase Technique for Brushless DC Motor Control in High Speed Region

Brushless DC motors are more and more popular in industrial and house appliance application thank to their constructional advantages. Control of these drives in high speed region is however relatively difficult. In order to extend the speed range of the drive, it is common to control the phase-current to lead the phase back EMF by an “advance angle”. It is based on the method of “phase advance approach”, which was first proposed in 1995. The studies in literature have focused on finding the exact advance angle. In general, the previous methods to calculate the advance angle have been complicated. In this paper, the authors propose a new equation that makes the computation of advance angle become simpler. The operation of the drive in high-speed region has been verified by simulation in Matlab/Simulink and the results have demonstrated the validity of the algorithm.