A study on 4-layer hybrid winding layout of the IPMSM and location of the permanent magnets

IPMSM with more than 10KW, which is used for HEV, has lower Ld-Lq since a groove was made on the Q-axis flux path of the rotor to reduce the eddy current loss in the permanent magnets. Therefore, a high reluctance torque and wide operating range can´t be expected. Also in the winding layout, concentrated winding may widen the operating range; however this is needed the fractional slot or leads to reduce the power density. In this paper, 4-layer hybrid winding (concentrated + distributed winding) layout designing to make the operating range of the traction motor, which is used for HEV and EV, widening and redesigning the permanent magnet´s location are suggested. This method can widen the flux-weakening area compared to the conventional winding layout, and by adjusting the number of windings it would also make the air-gap flux density more sinusoidal. Moreover, it would highly increase the power density compared to the distributed winding.