Abstract: Photovoltaic inverter，charging pile，energy storage converter，wind power converter and other

common power electronic equipment are three-phase high frequency AC/DC/DC converter，which is widely used in

industrial and civil fields. Due to the fast switching capability of three-phase high frequency converter，its high

frequency harmonic components can' t be ignored. The traditional switch model is difficult to analyze，and the average model ignores the high frequency components，which have shortcomings in analyzing high frequency harmonics.Based on this，a broadband equivalent modeling method of three-phase high frequency AC/DC/DC converter was proposed. Compared with the traditional modeling methods，the proposed model is based on the normalization method to simplify the model form，use complex convolution Fourier series to analyze low frequency signal and high frequency signal simultaneously. The simulation model was built in Matlab/Simulink，and the correctness of the proposed method was verified by comparing the simulation data and experimental data of the model in different working states.

      Key words: three-phase inverter；high frequency harmonics；equivalent modeling；normalization；Fourier series