Design And Research Of A Plug-in New Energy Bus Powertrain Integrated Thermal Management System

With the gradual promotion and popularization of new energy vehicles,the safety issues of new energy vehicles are getting more and more attention.As the key to ensure the normal operation of the new energy key assembly,thermal management system related research is also getting more and more attention.This thesis takes the plug-in new energy bus powertrain integrated thermal management system development project as the research object,carring out the modeling and analysis of the thermal model of each powertrain system,completing the heat loss calculation,building the thermal management system simulation model simulation platform to assist the matching selection design of circulating water pump and cooling fan,desiging temperature control strategy of circulating water pump and cooling fan,and finally verifying the rationality of thermal management system matching and effectiveness of temperature control strategy through simulation platform and actual vehicle test.The main research content of the full text is divided into the following parts.(1)The thermal model of powertrain integrated thermal management system was studied.The heating mechanism of the main heat sources,i.e.motor(driving motor and generator)and engine,was analyzed,and the corresponding parameters were calculated according to the actual situation;Secondly,the key issues of the thermal model were analyzed and the overall simulation model was established.(2)According to the parameters of the whole vehicle,the overall control scheme of the heat management system was designed with the objective of minimizing the heat consumption of the power assembly system and the heat management system.The operating logic of heat management system was analyzed,and the matching design of radiator,water pump and fan was completed according to the heat dissipation demand of the system.Using the simulation model of study(1)The simulation results and test results show that the relative error between the two is within 5%,which indicates that the accuracy of the thermal management system simulation model established meets the requirements.(3)According to the overall control scheme of heat management system designed in study(2),bench test and vehicle test were carried out.The MAP diagram of motor efficiency was measured in bench test,the actual effect of the ITMS is verified by the actual vehicle test,according to the national standard and Cummins engine cooling system verification process standard.The temperature difference between engine coolant outlet temperature and ambient temperature is 85.16?-32.34?=52.82?<55? at high speed,meeting the test requirements.Therefore,the ambient temperature is50.88?-32.34?=18.54?< 20?,meeting the test requirements.Therefore,the research results achieved the goal of vehicle and engine manufacturers.Aiming at minimizing overall system energy consumption,taking into account the performance requirements of each subsystem,the optimized control method is used to achieve intelligent control of the system,optimizing control method to reduce overall system energy consumption while reducing the complexity of the system.This is a useful exploration of this paper in the integration of new energy vehicle systems and an important innovation in the technical method.Use simulation analysis software to realize the simulation analysis of the integrated thermal management system,and build a real vehicle test platform to provide a practical reference for the development of new systems and new models,improving the depth and level of intelligent and digital design and having a better research significance and application value.