Loss Analysis And Magnetization Characteristics Of Electrical Steel Under Interharmonic Excitation

The problem of power quality has been widely concerned by scholars in related fields since its birth.With the application of a variety of new transmission technologies,the rapid development of the new energy industry,and the use of a large number of new power electronic equipment,a large number of interharmonic sources have been introduced into the power grid,and the power quality problems caused by interharmonics have gradually become an important research direction in the electrical field.In this paper,an Epstein square circle is used to build a ferromagnetic material measurement platform that can simulate various working conditions,and the measurement platform was used to measure the induced voltage,excitation current,hysteresis loop,magnetization curve and loss of electrical steel sheet under interharmonic conditions.The influence of different frequencies and different contents of interharmonics on the loss characteristics of electrical steel sheets is analyzed,and the spectrum analysis of the excitation current of the square coil is carried out;analyzed the shortcomings of the traditional Bertotti loss separation model,and on this basis,some parameters of the model are optimized,obtained an improved loss separation model for sinusoidal conditions,the improved model is used to calculate the loss separation of various types of steel sheets,and the calculation results of some parameters are given,it can provide a reference for the loss calculation of other magnetic materials;Based on the improved model,through theoretical analysis and data verification,abtained a loss separation model suitable for interharmonic conditions,after calculation,the model can accurately predict the iron loss of electrical steel sheet under interharmonic excitation,the model has high engineering application value;Using B27R095 silicon steel sheet to manufacture a laminated core model,and build a laminated core magnetic performance measurement platform,measured the excitation current,magnetization characteristics and various losses of the laminated core under interharmonic excitation,the spectrum analysis of the core excitation current is carried out,and the similarities and differences in various aspects of the electrical steel sheet and the product-grade laminated core are summarized.