Thermal Representation of Interior and Surface Mounted PMSMs for Electric Vehicle Application

Due to high torque and power density, permanent magnet synchronous motor usually faces significant challenges for thermal stability. Moreover, it becomes difficult to keep thermal stability within the motor because the magnets that are embedded in the rotor or mounted on the rotor surface are susceptible to heat. Therefore, thermal investigation is one of the mandatory procedures during design phase of the permanent magnet synchronous motor to ensure thermal stability. In this paper, a universal lumped parameter thermal network model has been proposed for thermal design of all types of permanent magnet synchronous motors which can be used for wide range of winding configurations and any position of magnets in the rotor. The proposed analytical thermal model has been used to check the thermal performance of both newly designed interior and surface mounted permanent magnet synchronous motor prototypes for future electric vehicle application. Further, a numerical thermal model has been proposed also to check temperature distribution throughout all parts of both motors and for comparison.