Temperature Rise Calculation And Heat Dissipation Design Of Integrated Lighting Power Supply

The increasing power density of the integrated lighting power supply has triggered high heat generation of the power supply,reducing the life of the power supply.At the same time,the LED chip of the lighting lamp is also a heat source,which will be thermally coupled with the power supply heat,intensifying the heat of the power supply.In order to dissipate heat from the power supply,the housing of the lighting is usually made into a "louvered" heat sink structure.This housing structure makes the lighting lamp larger,limiting the application of lighting scenarios.Therefore,accurate temperature rise calculation and reasonable heat dissipation design for lighting power supplies are important to improve the life of power supplies and expand the application scenarios of lighting lamps.The object of this Thesis is an integrated lighting switching power supply（hereinafter referred to as power supply）,which is its own heat source and requires a sealed working environment.For its special working environment,the following work is carried out.First,analyze the structure of the lighting lamp and the temperature rise of the LED,determine the heat source and distribution of the lighting lamp,and give the calculation method of the junction temperature of the LED chip.The working principle and the actual operating conditions of the power supply are analyzed and calculated,and the operating conditions of the power supply are solved by analyzing the topology of the power supply and the efficiency at different output currents.Then,the losses of power supply MOSFETs are theoretically analyzed and calculated using empirical formulas;the losses of power supply transformers are theoretically analyzed and calculated using empirical formulas combined with software simulations.Combining the loss calculation results with software simulation,the temperature field simulation of the power supply is performed to obtain the temperature distribution of the lighting lamp and the exact temperature rise value of each device of the power supply.The existing thermal design of the power supply is analyzed to address the problems of large size,easy failure and high maintenance cost of its thermal structure.The thermal layout of the power supply’s devices is redesigned using a simulated thermal annealing algorithm,taking into account the power supply’s electromagnetic compatibility performance.The power supply transformer is redesigned to use a planar transformer instead of a wire-wound transformer,and the power supply transformer module is designed for heat dissipation.Finally,an experimental platform is built to produce a power supply test prototype and conduct temperature rise measurement experiments on the power supply to verify the accuracy of the temperature rise calculation results and the effectiveness of the heat dissipation design.It provides a reference for the temperature rise calculation and heat dissipation design research of integrated lighting power supply,which has certain engineering application value and guidance significance.