Research On Matching And Control Strategy For Cooling System Of Driving Motor In Pure Electric Bus

As the development strategy of China's automotive industry,the new energy vehicle industry can effectively relieve the increasingly severe energy and environment problems.The driving motor of a pure electric bus as the only power source of the vehicle,its reliability directly affects the performance of the electric vehicle.In order to prevent the permanent magnet of the motor from demagnetizing due to the high temperature,even affects the life of the motor its controller and vehicle safety.The temperature control of the driving motor and its control system plays a key role.Therefore,it is of great significance to match the cooling system of the driving motor of the pure electric bus reasonably and make a scientific and effective control strategy.Based on the Jilin province high tech Electric Vehicle Co.,Ltd.and Jilin University signed the "pure electric vehicle control strategy and control system development" technology development(Commission)project,the company and the group on the basis of existing technology,to carry out the analysis of structure characteristic of the drive motor and its control and heat radiating mechanism;The calculation of the loss of the motor and its controller under different working conditions;Matching the design of electric circulating water pump,cooling fan speed continuous adjustable cooling system;Formulate the temperature control strategy of the electric water pump and the cooling fan;A joint simulation platform for cooling system model is built;The simulation of the rationality of the matching of the cooling system and the validity of the temperature control strategy is realized;The main research content of the full text is divided into the following parts:1.The structure characteristics and heat generation mechanism,main heat sources,heat dissipation ways and influencing factors of the driving motor and its controller are analyzed.The heating power of the motor body and its controller under rated working condition and peak working condition is calculated respectively.2.The characteristics and main layout of the cooling system of the electric motor drive motor and its controller are analyzed.The arrangement scheme of series cooling for motor and controller is determined,and the type of cooling water channel of motor is selected andthe parameters are designed.The calculation and selection of the main components such as the radiator,the cooling fan and the electric pump in the cooling system are completed.The selected components are checked and calculated are completed at the end.3.The temperature control strategy of the drive motor cooling system was formulated and the temperature control strategy was divided into the threshold control mode and the fuzzy control mode;the selection of the threshold value in the pump and fan threshold mode was completed;the electric water pump and heat dissipation were completed.The fan fuzzy control strategy was formulated specifically;a fuzzy controller and the corresponding control rules were designed.4.The AMESim physical model of vehicle with cooling system and the temperature control strategy Simulink model were built;The co-simulation of the physical model and the system control model of the drive motor cooling system was completed,and the cooling system was subjected to uniform conditions and cycle conditions.The simulation test was conducted;the temperature control effect and power consumption of the designed motor cooling system under different working conditions were analyzed;the rationality of the matching design of the cooling system and the effectiveness of the temperature control strategy formulation and the energy-saving effect of the cooling system were verified.