Research On Power Core Loss Modeling Of High Frequency Inverter

With the rapid development of power electronic technology,magnetic components are widely used and have become the core components of various switching converters.The high-frequency inverter is a switching converter widely used in the industrial neighborhood.In order to improve the power density of the circuit and the efficiency of the whole machine,high-frequency magnetic components with small volume and light weight are usually selected,but the high-frequency The working conditions will make the magnetic components overheat,which will seriously affect the reliability of the high-frequency inverter.Therefore,the optimal design and rational use of the magnetic components are of great significance to improve the performance of the high-frequency inverter.Based on this purpose,this paper establishes a high-frequency inverter core loss calculation model with convenient engineering application and clear theoretical concept.In this paper,based on the loss characteristics of magnetic components,the components that make up the core loss are introduced in detail.The core losses are modeled and classified according to different excitation conditions.At the same time,a variety of measurement methods for magnetic core loss are introduced.Accurate measurement of magnetic core loss is an important prerequisite for analyzing magnetic core loss.This paper expands on the scope of application and advantages and disadvantages of various methods.The measurement selected in this experiment is The method is the oscilloscope method.At the same time,two types of errors that affect the experimental data and improvement schemes are also mentioned.Secondly,the working characteristics of the magnetic components in the single-phase full-bridge inverter circuit are introduced,the relationship between the excitation waveform and the magnetic flux density amplitude under different control strategies is discussed,and the relationship between the hysteresis loss and the eddy current loss in the unit switching cycle is constructed.Variation characteristics and methods of averaging modeling.In addition,this paper focuses on analyzing the influence of the modulation degree and carrier ratio on the power core loss in the high frequency inverter circuit.Taking the power inductor in bipolar DC/AC circuit as the main research object,combined with the specific circuit analysis,it is considered that the excitation signal at both ends of a fundamental wave cycle power inductor is composed of multiple square waves with different amplitudes and duty ratios that vary according to sinusoids.The core loss of the high-frequency inverter is modeled with the idea of accumulating,summing and averaging.Taking the modulation degree and the carrier ratio as two variables,the loss models of the two and the hysteresis loss and the eddy current loss are established respectively,thereby deriving the calculation model of the core loss in the high-frequency inverter.Taking the above-mentioned content as the theoretical basis,this paper uses MATLAB to build a simulation model to simulate the changing trends of related variables such as magnetic flux density amplitude and eddy current loss in the inverter power core loss calculation model,and build a bipolar DC/AC magnetic field.The core loss test platform is used.Finally,the accuracy of the high-frequency inverter power core loss model is verified through the simulation model and experimental data,and the influence of modulation degree and carrier ratio on the high-frequency inverter core loss is pointed out.The prediction of core loss under excitation is of great significance.