Modeling and Control Strategies of the Thermal Management System for Electric Vehicles

The electric vehicle thermal management system is a critical sub-systems of electric vehicles, and has a substantial impact on the driving range. The objective of this paper is to optimize the performance of the heat pump air conditioning system, battery, and motor thermal management system by adopting an integrated design. This approach is expected to effectively improve the COP (Coefficient of Performance) of cabin heating. An integrated thermal management system model of the heat pump air conditioning system, battery, and motor thermal management system is established using AMEsim. Key parameters , such as refrigerant temperature, pressure, and flow rate at the outlet of each component of the system are compared with the measured data to verify the correctness of the model established in this paper. Using the established model, the impact of compressor speed on the heating comfort of the cabin under high-temperature conditions in summer was studied, and a control strategy for rapid passenger compartment cooling is proposed. Additionally, a hybrid cooling strategy was established to address the priority issues of cabin and battery cooling, and compared with traditional cooling strategies in terms of cooling time and accuracy. The results demonstrate that the hybrid cooling strategy is capable of simultaneously cooling the cabin and battery if ambient temperature is 40°C. Compared with traditional methods that prioritize cooling either the cabin or the battery, the hybrid cooling strategy enables the rapid cooling of the battery while maintaining the cabin temperature comfort, and significantly reduces the discomfort time of passengers in the cabin from over 300 seconds to 80 seconds.