Rotor eddy-current loss of permanent magnet machine in brushless AC and DC modes, used for deep-sea HUV's propeller

Permanent magnet brushless motor used for deep-sea human occupied vehicle's (HUV's) propeller was studied in this paper. Based on analyzing the influences of waveform of phase current on flux density in air gap, rotor eddy-current losses were determined in BLAC and BLDC modes. This paper proposed that rotor loss is the minimum in BLAC mode. In BLDC mode, with optimal commutation advance angle (20°), rotor loss is the lowest. Finally the temperature distribution of the motor was gained considering the rotor eddy-current loss.