Electro-Thermal Analysis of Permanent Magnet Synchronous Motor for Electric Vehicles

Permanent magnet synchronous (PMS) motors are frequently used in electric vehicles because of their high power density, stable output torque and low noise. During the operation of an electric motor, some of the electrical energy is converted into heat. The rise in motor temperature hampers motor performance (power output, demagnetization, breakdown of winding insulation, efficiency and component lifespan). The losses occurring in electric motors during operation mainly include: stator loss, winding copper loss, rotor iron loss, eddy current loss in magnets and mechanical losses. The life and operating reliability of a motor depends on the thermal performance of the motor. This paper describes a detailed procedure for an indirect coupled analysis between Ansys Maxwell and Ansys Fluent, in order to predict critical thermal characteristics of the motor and cooling jacket. The main objective of this paper is to model the PMS motor with a cooling system based on input electrical and geometrical parameters. Computational fluid dynamics (CFD) simulation was performed by applying thermal boundary conditions obtained from the Electro-Magnetic simulation. A thermal map of the PMS motor was created along with identification of key hotspots inside the motor.