Research On The Core Loss Of Magnetic Components In Power Electronic Converter

With the fast development of power electronic technology, magnetic component hasbeen widely used, and become one of the most important parts of the power convertersystem. Its volume and losses occupy a great proportion of the whole converter, and it has adecisive influence to the efficiency and the power density. Therefore, the optimaldesign and reasonable application of the magnetic component has a vital significance to theperformance of the converter. And the accurate measurement and calculation is theprerequisite and necessary condition of that all.This paper analyzes the composition and principle of the core losses firstly, anddescribes several typical calculation models. Early models are almost only applicableto sinusoidal excitation. And then some scholar proposed a series of improvement modelsfor the non-sinusoidal excitation in the converter, such as Preisach model, Fourier model,modified Separation Calculation model, modified Steinmetz Equation, etc. The author hasmade a multianalysis comparison to the precision and applicable scope of these models, andverified those through experiments.Accurate measurement is the foundation to the analysis and calculation of core losses.Several common loss measurement methods are introduced in the article. The author hasmade certain analysis to the respective applicable scope and disadvantages, then chose themeasurement with digital oscilloscope as the experimental method. We also found that thewinding loss and phase angle error are the main source of core loss measurement error, andanalyzed the degree of influence on the measurement results. The windinglosses can be separated with an additional wind, and the phase of the voltage and currentcan be reduced with an appropriate low-loss capacitor or hollow inductor, then theinfluence of the phase angle error can be greatly weakened. The experiment andsimulation have also proved that.The application of the modified Separation Calculation model and modified SteinmetzEquation in DC-DC and DC-AC circuit was derived based on the previous work, and had been well verified by experiment. The core losses of the filter inductor in the Inverter arecomposed of the high-frequency loss and the fundamental-frequency loss. A new methodto separate two parts of the core losses was proposed at last, which made great sense to thedesign of the magnetic components and the core loss prediction.