Study Of Co-Simulation And Control Technology For Electric Vehicle Battery Thermal Management And Air Conditioning Systems

For pure electric vehicles, it has been difficulty for traditional air cooling methodto meet the cooling requirements of battery pack at a condition of high temperature,high-power discharge and other harsh environments. It is essential to develop efficientpower battery thermal management system, in order to make the most of the limitedbattery energy, give full pay to the performance of power battery, improve life cyclesof power battery and ensure the safety of battery power.This paper summarizes and analyzes the research status and development trendof battery thermal management technology and air-conditioning technology. And then,from the perspective of vehicle thermal management, a new structure of air conditionsystem considering battery thermal management is proposed, that is a structure takingpower battery as a load of air condition system and making use of the cold airproduced by air condition system to cool the power battery. The main contents of thispaper are fallowed:Firstly, research the temperature characteristics and cooling characteristics of. By the analysis of experimental data, it is clear that the suitable operatingtemperature range of is18-45degrees Celsius. From the perspective ofheating mechanism of lithium-ion batteries, the heat generation and transfer model ofis established, and then by calculating, the ideal cooling power requiredunder different speed and ambient temperature is obtained.Secondly, complete the parameter matching and selection of key components ofair conditioning system for electric vehicle. This paper presents a new airconditioning system considering thermal management of battery pack, and accordingto the structural characteristic of the system, its driving mode is divided into4modes.On the base of mode division, this paper calculates the heat load value of thepassenger compartment and the battery pack, and taking the sum of the two values asthe peak heat load of new air conditioning system. Thirdly, write the control strategy of new air conditioning system. The new airconditioning system must be flexible in switching among various operating modes, inorder to meet the cooling requirements of the passenger compartment and powerbattery. To, its temperature should only be controlled within the appropriatetemperature range, so, the temperature control of can use logic thresholdcontrol strategy. To passenger compartment, its temperature should be controlledaround the appropriate temperature, in addition, human·s perception of temperature isfuzzy, so, the passenger compartment·s temperature control can use fuzzy controlstrategy.Finally, complete the modeling and co-simulation of the new air conditioningsystem. According to modular modeling thought, the new air conditioning system isdivided into four modules, including passenger compartment one-dimension heat loadmodule, battery pack three-dimension thermal load module, air conditioning controlmodule, and passenger compartment temperature calculation module. Based onSimulink and Fluent, under typical operating conditions, co-simulation is taken for thenew air condition system to verify its legitimacy.