Design And Development Of Vehicle Power Supply Controller

Relay plays an important role in vehicle control.However,due to the shortcomings of traditional mechanical relay,such as easy ablation and failure of contact,slow switch speed,a sound of absorption and electromagnetic interference,it cannot meet the requirements in many application scenarios.Intelligent MOSFET,as a new type of load switch,emerges on this basis.Based on the cooperation project between school and enterprise,a high current vehicle power supply controller with CAN bus data communication and alarm function is designed by using the switching characteristics of MOSFET.The main work of this paper includes:At first,the purpose and research status of electronic relay at home and abroad are introduced,as well as the design index and technical difficulties of the controller are analyzed in detail.Then the overall design of the vehicle power supply controller is carried out,and the hardware and software design schemes are formulated.In terms of hardware,Infineon XC2234 L chip is selected as the main controller,and the hardware circuit is designed by modular design method,taking into account the electromagnetic compatibility and anti-interference performance.The circuit board schematic is drawn by Altium Designer to complete PCB wiring and fabrication.In terms of software,we use Dave to configure Infineon XC2234 L chip to generate code framework,write A/D acquisition and communication driver code in the Tasking compiler,and design monitoring software in Visual Studio to monitor the temperature,input and output voltage and input current of the controller,which can realize the collection,display,monitoring and alarm functions of communication data.In the case of large current,the controller has a serious heat generation.Aiming at the problem of high temperature rise of the controller,this paper makes a simple simulation of heat dissipation of MOSFET on the circuit board in ANSYS Icepak,and compares the effect of auxiliary heat dissipation by adding radiator.After the simulation,this paper improves the layout and lead of MOSFET,improves the structure of heat dissipation copper,and adds thermal conductive silica gel etc.The test results show that the cooling effect is obvious.After completing the welding and debugging of the prototype,a large number of software and hardware debugging,CANTest communication and functional stability experiments have been carried out in the laboratory and enterprise.The final test results show that the controller can satisfy the design requirements well and control the load of 200 A high current steadily.the temperature of MOSFET is controlled in a reasonable range.The stability of the controller is verified,the life and interruption ability of the controller are greatly improved,and the final product is put into the market.