The current interruption test based on an LC resonance circuit for hybrid DC circuit breakers (HVDC CBs) is widely employed to characterize the current interruption capability of CBs. In order to ensure a high-fidelity replica of the fault current in a high voltage application

this paper first proposes an equivalent model of the test circuit

where not only parasitic resistances but also the threshold voltages and on-state resistances of various semiconductor devices are considered. Moreover

the analytical formula of the test current is derived by including the working principle of the HVDC CB. Secondly

the parameter extraction method

which combines finite element analysis and measurements by an impedance analyzer

is given in this paper. The extracted result implies that

in current interruption transients

equivalent resistances of 500 k V CB are as large as 535 mΩ

which have a significant influence on current waveforms. Thirdly

the 34 kV/25 kA current interruption test for the 500 kV CB is conducted. The measured results are proved to be consistent with the analytical results obtained from the proposed model

and the relative error is less than 2 %.