Design and Comparison of Different Rotor Topologies at Liquid-Cooled Permanent Magnet Synchronous Machines for Electric Vehicles

This paper presents results related to the design and comparison of two 150 kW liquid-cooled interior permanent magnet synchronous machines (IPMSM) with different rotor topologies, designed for electric vehicles (electric buses). The study is performed starting from a set of performance requirements of the traction motor. The cogging torque, back-electromagnetic force and the motor performances are analyzed. Also, a thermal steady state analysis at rated power and speed is performed and presented. The design of the machines is made using the Altair FluxMotor software, which combines analytical calculation with finite element method.