Adjustment of hall sensor position in doubly salient permanent magnet motor

For the doubly salient permanent magnet (DSPM) motor, position sensors are necessary to provide the correct rotor position for the motor controller and correct commutation signals. Two basic position adjustment methods are given based on a 12/8-pole flume-rotor DSPM motor. Three Hall sensors mounted on its rotor part can obtain position signals. But due to the non-sinusoidal winding back electro motive force (EMF) or asymmetry of three winding EMFs caused by the motor, the fabrication and other reasons, it is difficult to adjust all Hall sensors to meet their ideal position relationships. Thus a novel adjustment method-2 by the coarse-adjustment in the generation state and by the trim-adjustment in the motor-driven state is proposed. Firstly, Hall sensor positions are coarse-adjustment when DSPM is used as a generator. Then by the basic adjustment method-2, the Hall positions are trim-adjusted when DSPM is used as a motor. The symmetry of non-conducting winding current tails and the maximum overall efficiency are used as the adjustment rule. The method is confirmed to be correct and feasible in the applications of DSPM motor.