Research On Hysteresis Characteristics Of Electrical Steel Under Different Excitation Conditions Based On Preisach Theory

With the rapid development of China’s power industry,higher and higher requirements have been imposed on the power supply quality,safe operation,and technical performance of transformers and other electrical equipment.Hysteresis is one of the important characteristics of magnetic materials,the accurate simulation of hysteresis is related to the performance prediction and optimization design of electrical products such as transformers,and it has become one of the hot topics in the current magnetic field.In order to more accurately simulate the hysteresis characteristics of ferromagnetic materials and more easily solve the hysteresis problem in engineering applications,it is necessary to establish an effective hysteresis mathematical model to simulate and analyze the complex magnetization process of magnetic materials under actual working conditions.Based on the classic Preisach theory,this paper focuses on the hysteresis characteristics of electrical steel sheet,and in-depth studies its simulation methods under different excitation conditions.The main works are as follows:1.Based on the basic idea of the Preisach model,the Preisach distribution function is approximated as a Gaussian function,and based on the Preisach geometric description of different magnetization states of magnetic materials,the output expressions of the model under different magnetization states are obtained,and the static hysteresis model is constructed.The parameters of the model were identified using genetic algorithm.Based on the established Preisach model,the hysteresis characteristics of electrical steel sheet under DC excitation can be quickly simulated.2.Based on the magnetization mechanism of magnetic materials,the Preisach distribution function is considered as the product of two one-dimensional functions,and the distribution function is described as the form of the sum of m terms to improve the accuracy of the model.The Everett function and the dynamic susceptibility are obtained by integrating the distribution function.The integral is characterized in a closed form,and the obtained closed-form expression is applied to the Preisach model to establish a static hysteresis model and a dynamic hysteresis model,respectively,which can accurately simulate the hysteresis characteristics of electrical steel sheet under DC and AC excitation.3.Based on the product-grade core model,a magnetic performance test platform for the core model under harmonic excitation was established,and the hysteresis characteristics of the core model under different harmonic excitation conditions were tested.A Preisach hysteresis model suitable for harmonic conditions is established,the model uses magnetic induction intensity B as input,which weakens the effect caused by congruence of the classical Preisach model with magnetic field intensity H as input.Concentric hysteresis loops were used to determine the Everett function to simplify the calculation process.The Preisach hysteresis model based on this method can effectively simulate the hysteresis characteristics of electrical steel sheet under harmonic excitation.