A kind of broadband equivalent circuit model which is applicable for the insulated core transformer is proposed by way of analysis of the characteristics of the magnetic circuit of the high-frequency insulated core transformer and on the basis of the principle electromagnetic duality as well as the port network theory. The model consists of equivalent inductance of magnetic circuit

equivalent leakage inductance between coils

capacitance parameters and ideal transformer. The inductance parameter represents the magnetic field effect of the insulated core transformer and the capacitance parameter represents the electric field effect inside the transformer. The model is not only suitable for the insulated core transformer with high frequency

different number of turns and windings

but also has a definite practical significance for some other types of transformers. The parameter extraction method based on the theory of port network and the finite element analysis is proposed. All parameters of the broadband model are obtained by the use of finite element analysis

are compared and verified with combination of circuit simulation software. The output characteristics of the finite element analysis and the circuit simulation results show a good consistency

which verifies the effectiveness of the model.