In this paper

a method for establishing broadband equivalent circuit model of CVT is proposed.Firstly

the parameter S of a CVT is measured in the frequency band of the conducted interference specified by the international radio interference special committee（CISPR）.The parameters Z and H of the CVT are obtained by the calculation of parameter S.The frequency characteristic curve of the parameter Z of the CVT is divided into multiple resonant units.Then

each resonant unit is characterized by a simple equivalent circuit.The parameter of RLC element for each resonant unit can be obtained from the information of the resonant and dis-resonant point in the region.The whole model can be obtained by connecting the equivalent circuit of the multiple resonance units in series and the more accurate model is obtained by the use of the optimization algorithm.Finally

the equivalent circuit model for measuring parameter Z of the CVT is set up in the ATP/EMTP software.The transmission parameters of the established model is measured in the frequency range of 0.15～30 MHz by frequency scan method

and accuracy of the established model is verified by comparing the transmission parameter of the established model with the actually measured parameter H.