Thermal Analysis And Optimization Of BSG Controller Rectification System

In the engineering practice,the rectifier MOS tube of a certain belt-driven starter-generator(BSG)controller is unable to reach the design capacity due to poor heat dissipation,and the motor controller heat dissipation factors are analyzed.On the basis of this,taking the rectifier MOSFET of the BSG motor controller as the main research object,the professional thermal analysis software Flo EFD was used to thermally analyze the BSG controller,and the heat sink structure was optimized and experimentally verified.First,the difference between BSG system and traditional generator system is explained.The main heat source in the motor controller of BSG system is the synchronous rectifier MOS tube in the power module.The synchronous rectifier MOS tube and the heat source on the BSG rectifier system are calculated and analyzed in detail.According to the thermal characteristics of the heat transfer material,the advantages and disadvantages of aluminum,copper and aluminum alloy material radiators were analyzed,and the use of aluminum alloy materials for the radiator was determined.Using professional thermal analysis software Flo EFD,thermal simulation analysis of the BSG synchronous rectifier MOS tube and the main heat sources on the PCB board,comparing the maximum temperature of the synchronous rectifier MOS,the maximum temperature of the heat sink,the motherboard under different speed conditions of 2000r/min-6000r/min The maximum temperature of the PCB,the results show that the temperature of the synchronous rectifier MOS tube at the motor speed of 2000r/min exceeds the junction temperature after derating,and the radiator structure needs to be optimized.The paper carried out the optimization design and analysis of the heat dissipation structure of the BSG controller.Using Flo EFD to perform numerical simulation calculations to obtain the temperature field and flow field distribution of the original parallel fin radiator structure,it was found that the parallel fins have poor heat dissipation The air is in full contact with the heat dissipation,the influence of the deflector on the heat dissipation is studied,the radiator with three new fin structures of straight fins,bentfins and spaced fins is designed,and the three fin structures and fins are studied The influence of the coupling change of the number of teeth on the heat dissipation performance of the controller determines the appropriate fin structure type,and the control variable method is used to optimize the fin height and thickness to obtain the optimized scheme of the radiator structure.The optimized design of the heat sink structure can reduce the maximum temperature by 5.14?.The use of the guide plate can reduce the maximum temperature of the MOS tube by 7.09?.Finally,the paper proves the correctness of the optimized design of the heat sink structure through experiments.The research results have solved the existing controller heat dissipation problem and provided a reference for the research of other controller radiators.