Thermal Analysis of Permanent Magnet Motor for the Electric Vehicle Application Considering Driving Duty Cycle

A lumped parameter thermal analysis of permanent magnet motor by considering real driving duty cycle is presented. As driving motors of electric vehicle, permanent magnet motors exhibit high efficiency and high power density. However, they are susceptible to suffer irreversible demagnetization and insulation failure of coils under severe thermal condition. Therefore, it is essential to accurately evaluate heat losses and precisely predict temperature distribution in driving motors under the real driving duty cycle. In this paper, an improved core loss model is employed and implemented by using finite element method. The thermal behavior of the driving motor is analyzed by means of lumped thermal parameter method. A test bench has been set up to measure the temperature distribution in the driving motor. The calculation and experiment results are compared and discussed.