An Experimental Methodology for Modeling Surge Protective Devices: An Application to DC SPDs for Electric Vehicle Charging Stations

This work introduces an experimental methodology for time-domain modeling of low-voltage surge protective devices (SPDs), accounting for their sparkover performance as well as their resistive, inductive, and capacitive behavior. The modeling procedure is demonstrated through an application to a combination type SPD connected to the DC side of electric vehicle charging stations. An equivalent circuit model is developed based on experimental records acquired from applied voltages and currents of a wide frequency range and energy content. The developed lumped-circuit model yields results in very good agreement with experimental data regarding sparkover voltage, residual voltage, and energy absorption of SPDs, as illustrated through ATP-EMTP simulations. The proposed methodology can be an effective tool for surge protection and insulation coordination studies.