In view of the fault of UHV CVT due to disconnector operation at the serial compensation platform side at certain UHV substation

the accurate UHV CVT broad band equivalent circuit model is set up

which is helpful for simulation study of the transient fault of the CVT.In this paper

the broad band model for UHV CVT is set up by the model set up method which is based on the genetic algorithm.Firstly

the vector network analyzer（VNA）is used to measure the broadband frequency-dependent impedance of the capacitor divider and the scattering parameter of the electromagnetic unit.Then

the broadband modeling method based on genetic algorithm is used to set up the broad band equivalent circuit model of capacitor voltage divider and electromagnetic unit respectively and the model established is strict passive.Finally

the impulse signal is applied on the primary side of the UHV CVT

the measurements are performed at different positions of the CVT.The UHV CVT circuit model is set up in the EMTP so simulate the test process.The correctness and effectiveness of the model is verified by the comparison of simulation result and the actual experimental result.