Research And Optimization Design Of High-Frequency Transformer For Low-Voltage And High-Power Switching Power Supply

High-power switching power supplies are increasingly widely used in subway traction,aerospace,medical equipment and other fields,and the output power is also increasing.As the core magnetic component of the high-frequency transformer,its loss and volume greatly affect the overall performance of the high-power switching power supply.Therefore,the research and optimization design of high-frequency transformers are of great significance to improve the overall performance of switching power supplies.The research object of this project is the low-voltage and high-power switching power supply applied to the trip test of DC circuit breaker in the traction power supply system of metro traction power supply,and the loss calculation and optimization design method are studied with the high-frequency transformer as the research focus.Taking the high-frequency transformer as the research focus,the loss calculation and optimization design method are studied.In switching power supplies,because the voltage excitation on the primary side of the transformer is often a nonsine wave such as a square wave,this makes it difficult to calculate the core loss.In order to accurately evaluate the core loss,this paper corrects the calculation formula of non-sinusoidal core loss based on the typical waveform generated by the phaseshifted full-bridge circuit on the primary side of the high-frequency transformer,and the simulation verifies that the modified improved Generalized SE(IGSE)formula has high accuracy.In addition,the eddy current effects of different windings were analyzed,and the optimal thickness and structural arrangement of copper foil windings were studied and analyzed,which provided a basis for the selection and design of high-frequency transformer windings.Starting from the goal of reducing the volume and loss of high-frequency transformers,this paper proposes an improved method for the problem of precocious convergence of non-dominated sorting genetic algorithm(NSGA-II),which reduces the probability of precocious convergence and has high reliability.The traditional AP method and the improved algorithm are used to design the high-frequency transformer,and the superiority of the optimized high-frequency transformer is verified by comparing the calculation results.In this study,the parameters of a single transformer are 10 k Hz/10.288 k W,and the simulation model of the transformer before and after optimization is established,and the simulation results show that the overall loss of the optimized high-frequency transformer is reduced by 80 W compared with the traditional AP design,and the efficiency is increased by 0.8%.The experimental results show that the optimized high-frequency transformer has high efficiency,can meet the high-power output requirements of switching power supply and has good output performance,which verifies the practicability and effectiveness of the optimization design method in this paper.