Temperature Distribution and Thermal Damage of End Winding in the Vehicle FESS

Flywheel energy storage system (FESS) has broad application prospects in new energy vehicles, but the lifespan of permanent magnet synchronous motor/generator (PMSM/G) insulation is an important factor restricting its development. This article focuses on the thermal damage problem of the end winding of PMSM/G in vehicle FESS, systematically revealing its temperature distribution characteristics, strain characteristics and insulation crack propagation mechanism. Firstly, the heat sources and dissipation of the PMSM/G in the charge, standby and discharge states are analyzed, and the insulation thermal stress and crack propagation are studied. Then the temperature, strain and crack stress intensity factor of the end winding are calculated by finite-element analysis. Finally, the differences in temperature and strain of the PMSM/G end winding under three states are verified through experiments. This research provides support for the end winding heat dissipation design and insulation system optimization of vehicle FESS.