Development of multi-layer interior permanent magnet synchronous machine for vehicle

Interior permanent magnet synchronous machine has many advantages such as reluctance torque, high power density, and wide speed range due to the rotor structure with saliency. In addition to, multi-layer interior permanent magnet synchronous machine (multi-layer IPMSM) which adopts multi-layer magnet structure in the rotor has large saliency and improved characteristics, such as high starting torque and suitability for constant power operation in the wide speed range, which are the useful features for vehicle application. In this paper, design strategy considering various design constraints in the 42 [V] ISG applications is presented and a practical design example of the 8-pole multi-layer IPMSM is shown. Analysis result and experimental data of manufactured one are shown and compared to verify the design process.