Magnetic Form Which Applied C Shaped Magnet for Hybrid Electric Vehicle 2021-01-0778

Currently, electrification for vehicles such as battery electric vehicles (BEV), plug in-hybrid electric vehicles (PHEV), fuel cell electric vehicles (FCEV) and hybrid electric vehicles (HEV) are attracting a great deal of attention, due to the urgent need to reduce CO₂ emissions created from transportation and energy dependency on crude oil. Honda has set a target achieving two-thirds of total global sales as electrified by 2030. A traction motor is one of the essential components for electrified vehicles. Generally, Interior Permanent Magnet Synchronous Motors (IPMSMs) are used as traction motors due to their high torque and power density, high efficiency and ease of use. The design of rotors, which consist of magnets and electrical steel sheets, is important for IPMSMs since not only average torque, efficiency and quietness depend on it, but also cost. We have developed a novel rotor, which allows for a degree of freedom in the shape of the magnets. In the proposed rotor, first, the shape and position of the magnets are determined parametrically under manufacturing constraints. Then the shape of the electrical steel sheet is determined by the ideal flux-line using maximized L_q-L_d. This means combining q-axis flux and parametric optimization for practical design of the rotor. We also reduced torque ripple through use of magnet position and dimple design. Rotors that are used in electrified vehicles are rotated at a maximum speed without gearing, so the rotor has to be designed by taking into consideration not only magnetic but also centrifugal forces. Therefore, we studied mechanical simulation with the optimization for magnetic performance while limiting maximum stress and displacement.