A high switching overvoltage will occur when hybrid high voltage DC breaker（H-HVDCB） operates in voltage-source-converter-based high voltage direct current（VSC-HVDC） grids. At present

there is no research on the simulation model of H-HVDCB for switching overvoltage simulation. Aiming at the mainstream H-HVDCB

we put forward a port equivalent model of H-HVDCB for switching overvoltage simulation in VSC-HVDC grids. The calculation method of the parameters in the model is also introduced. A significant advantage of this model is that it only needs to know some original design indicators and the action time of some individual components when modeling

and does not involve the internal structure and parameters of the H-HVDCB

which reduces the difficulty of modeling during the engineering design phase. The breaking test of the H-HVDCB is carried out in the laboratory. Meanwhile

the simulation model of the test H-HVDCB is established by using the proposed method. The comparison between the experimental results and simulation results shows that the proposed model has high simulation accuracy when simulating the overvoltage of H-HVDCB. The maximum error of the peak voltage during the test is only 3.1%. Finally

the simulation model of Zhangbei project verifies that the proposed model also has high simulation accuracy in power grids. The maximum error of the peak voltage is only 3.3% in multiple simulations.