Simulation And Design Of Switching Power Supply Magnetic Components Based On Finite Element Method

With the development of power electronic technology, switching power supply isin the direction toward miniaturization, high frequency and high power density. Thedevelopments of switching power supply set a higher demand on the magneticcomponents. How to reduce the transformer loss and optimize the distributionparameters to meet the requirements of circuit has important significance to improve theperformance of switching power supply.This paper analyzes the high frequency effect on the transformer loss anddistribution parameters. According to the theory of finite element and the analyses ofnumerical calculation of electromagnetic field, the main steps of computational processare given. The effects of high frequency on transformer are discussed. Detailed analysisis completed by the application of circuit simulation software. Further, the authoranalyzes the causes and mechanism of the transformer loss and distribution parameters.This paper focuses on the calculation process and method of the transformer lossand distribution parameters by the application of the theory of finite element. Accordingto the structure of the transformer and some assumptions, the transformer3D model isestablished. Using finite element methods to carry on the numerical simulation of themodel, from which the loss and distribution parameters is compared with those by theanalytical method.Adjusting the winding layer space and the relative dielectric constant of insulatinglayer, the distribution parameters calculated by the finite element method are analyzedand compared. Further, using nonlinear regression algorithm to fit the surface of leakageinductance and distributed capacitance on the winding layer space and dielectricconstant, the author establishes corresponding mathematical model and analyzes it.Finally, the author changes the winding layer space in the experiments and measures theleakage inductance and output voltage peak to peak value of the switching powersupply.In the process of design switching power supply transformer, we can predict thetransformer loss by the above calculation method, whether or not to meet the systemrequirements. In order to obtain the distribution parameters reasonably meet therequirements of circuit, we establish the mathematical model of distribution parametersof transformer. Application of this method to realize the goal of transformeroptimization and design of switching power supply has vital significance in the theoryand practice.