Energy System Modeling of Liquid Cooled Propulsion Permanent Magnet Synchronous Motor for Electric Vehicles

Modeling of energy system is vital for efficient energy management of electric vehicles (EVs). As a core of EV powertrains, there are few relevant researches for the widely used liquid cooled permanent magnet synchronous motor (PMSM) system. To scientifically evaluate the benefits as well as the costs of forced liquid cooling system towards temperature-dependent mechanical power of EV PMSM, here, the effect of motor magnet and its temperature on PMSM mechanical performance are analyzed firstly. Then, the motor liquid cooling system with different layout is novelty involved in the PMSM system. Thirdly, the liquid cooled propulsion PMSM energy system for EVs is proposed. Finally, a case study is conducted based on proposed model by numerical methods under a given EV's practical conditions and shows about 1.5% enhancement in energy system output power. The proposed energy system model has laid a foundation for further management and optimization of EV PMSM liquid cooling parameters in order to obtain the highest system level output power.