A study on the optimum phase advance angle of high speed operation for 7 phase BLDC motor drives

The published papers of phase advance angle are proposed the in-phase concept which phase current compensates lagging angle based on back EMF because of increasing reactance at high speed. But this is not satisfied with performance of motor at very high speed. This paper describes the additional phase advance angle which 7 phase BLDCM is operated at very high speed with 20,000 to 25,000 rpm. It also proposes a method to predict optimum phase advance angle including in-phase angle and additional advance angle. Simulation results verify the need of additional advance angle.