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.