Structure Design And Optimization Of LED Headlam Based On Thermal Analysis

As an independent system of the vehicle, conflicts between heat and electromagnetic compatibility is getting increasingly sharp in LED automotive headlamp for LED chip of small size, high power and drive circuit of high working frequency. The paper takes a LED reflective headlamp model as the research object, accomplished thermal and electromagnetic compatibility design according to LED thermal properties and its driving circuit electromagnetic compatibility based on ANSYS. The main research contents are as follows:(1) The paper studies the influences of fins’thickness, height, spacing, base plate’thickness and surface radiance on LED array heat dissipation. During automatic simulation and optimization, the model’s geometric parameters, highest temperature and mass, thermal resistance are set as variables, constraint functions and objective function respectively. Results indicate that in the condition of85℃, the plug-in fin model has mass of0.2756kg, temperature rise of12.52℃and thermal resistance of1.026℃/W, which is better than cylindrical model.(2) When design the whole lamp set, the air intake grille is set at the fro nt bottom of the headlights, and the air outlet grille is set at the back top. Wh en the vehicle is moving forward, the airflow will be in the opposite directio n into the internal. This will increase the internal convection and improve th e cooling effect. The simulation results show that when the wind speed is at2m/s, this method can control the maximum temperature rise within10℃which meets LED heating standards(3) The paper studies application of heat pipe and micro-channel cooling structure on LED headlamp, which collects heat generated by the LED to the vent of the headlamp rapidly and then dissipates out. The results show that this two cooling structure have smaller space, and make the highest temperature of whole lamp control under10℃ (4) The electromagnetic analysis of HV9963and HV9930two LED driv er circuits show that drive circuit based on HV9930has a larger current indu ction intensity, E-field and H-field and far-field radiation intensity and broad er range than the drive circuit based on the HV9963. So HV9936should be c hosen as the drive circuit for LED lights.(5) Completed thermal analysis of HV9963LED drive circuit, adjust an d optimize it according to the simulation results, so it can work in normal am bient temperature.