Performance investigation of integrated thermal management system for electric vehicle with waste heat recovery of electric drive system

At low ambient temperatures, the battery discharge efficiency is low and the comfort of the cabin is poor, so it is inevitable to heat the cabin and the battery system to ensure the comfort of the cabin and the discharge efficiency of the battery. In this paper, an integrated thermal management system (TMS) model for pure electric vehicle (EV) with heat pump air conditioning (HPAC) and waste heat recovery (WHR) of electric drive system (EDS) is developed, and the model includes battery TMS, EDS TMS and cabin TMS. In the model, the battery is heated by motor WHR and reducer WHR, while the cabin is heated by HPAC and motor WHR, and different heating strategies are formulated at different ambient temperatures. In addition, in order to increase the temperature of the battery and the cabin rapidly, the motor blocking and motor inefficiency heating strategies are formulated to increase the waste heat (WH) recovered from the EDS to the cabin and the battery at low temperatures. The purpose of the TMS is to reduce the energy consumption (EC) of the EV for heating and increase the EV range under the premise of heating the cabin and battery at low temperatures. The results show that after using HPAC and WHR of the EDS instead of positive temperature coefficient (PTC) heater to heat the battery and the cabin, the battery state of charge (SOC) increased by 0.4 %, 0.8 %, 1.4 %, and 1.3 %, respectively, at ambient temperatures of −20 °C, −10 °C, 0 °C, and 5 °C after 6 NEDC cycles. And at ambient temperatures of −20 °C, −10 °C, 0 °C and 5 °C, the EV range increased by 31.622 km, 30.513 km, 17.494 km and 19.352 km, respectively.