Design And Implementation Of High Temperature Planar Transformer For High Power DC Switching Power Supply

Traditional switching power supply has a big bulk and can not work in high temperature environment,generally the highest temperature is about 100 °C.As the core device of the switching power supply.the transformer occupies the main position of the switching power supply,however due to the heat of high-frequency,transformer increases the system instability.Using high-temperature planar transformer which applies direct copper-clad alumina ceramic substrate can be a good solution to the traditional switching power supply transformer currently facing technical difficulties.In this thesis,the design and implementation of a high-temperature planar transformer for high-power DC switching power supply based on the switching power supply is studied.A planar transformer can be designed to achieve high temperature and high power density.This thesis mainly studies the planar transformer from two aspects:the design and implementation for high temperature planar transformer and the finite element simulation for transformer.The main work of this paper is as follows:In the design of high temperature planar transformer.First,the magnetic core material and structure of the transformer are discussed,and combining with the technical index of this design,the iron-nickel-molybdenum magnetic core and flat E-type magnetic core are adopted,which are high temperature magnetic core material.According to the temperature grade of the printed circuit board winding,the alumina ceramic which can withstand high temperature is selected as the substrate of the printed circuit board,and the winding traces of the transformer are directly laid on the ceramic substrate.Then,by analyzing several equivalent circuit models of the transformer,the appropriate equivalent circuit model is selected to design the transformer.Finally,the parameters such as the core size and the turn number of the transformer are calculated by utilized the AP method.According to the parameter calculation of the high-temperature planar transformer,designing the coil winding and elaborating the whole realization process of the high temperature planar transformer.The finite element simulation software is adopted to simulate the high temperature planar transformer,including electromagnetic simulation and temperature field simulation.Firstly,the theory of electromagnetic field and the finite element principle are analyzed in detail.Then the ANSYS Maxwell software is applied to simulate the static magnetic field and transient field of the planar transformer to obtain the transformer parameters,such as inductance and loss.Finally,the ANSYS Workbench was used to simulate the temperature field of the high temperature planar transformer,and the temperature distribution of the high temperature planar transformer was observed to verify that whether the designed high temperature planar transformer reaches the required temperature grade.From the experimental and simulation,the high temperature planar transformer designed in this thesis has the characteristics of high power density,low temperature rise and low leakage inductance and so on.It meets the design requirements and can meet the requirements of high power DC switching power supply.