Integrated Design Of Leakage Inductance And Insulation Of High-frequency Transformer

As the key equipment of photovoltaic DC conversion,the high frequency transformer not only needs to ensure that the parasitic parameters meet the requirements of the design,but also needs to conduct insulation design on its output side to achieve series high voltage output.Therefore,the calculation of parasitic parameters and the establishment of insulation design scheme have become an indispensable part of integrated design of transformer.Existing theories are not accurate enough in the calculation of transformer leakage inductance,leading to the deviation between the design value of leakage inductance and the actual value.In addition,there is no analytical theory to deal with the contradiction between leakage inductance and insulation at present,which leads to the failure of reasonable consideration in the integrated design of transformer.Therefore,this paper based on the background of the National Key Research porposes this topic of the high frequency transformer to deal with the above problems.This paper mainly includes three aspects: the calculation of transformer leakage inductance,transformer insulation design,and transformer comprehensive design.In part of leakage inductance of the transformer,the paper respectively analyses the leakage inductance of foil、round wire、litz windings transformer,and expounds the three kinds of the defects in the leakage inductance calculation of the above transformers,and puts forward a method to improve the accuracy of leakage inductance calculation of the foil transformer as well as a method for round/litz transformer.In the part of transformer insulation design,the numerical method and simplified analytical method of insulation design are analyzed,and some supplementary measures are adopted to solve the shortcomings of simplified analytical method.For transformer integrated design,the paper solves the contradiction between leakage inductance and insulation design by solving the inter-winding distance analytically,and the integrated design flow of high frequency transformer considering leakage inductance and insulation is given.Finally,the reliability of the above proposed methods and design process is verified by simulation and experiment.