The Damage Effects on Surge Protective Devices Caused by the Ground Potential Rise during the Initial Long Continuous Current Processes of Triggered Lightning Events

Based on the triggered lightning technology, this study carried out observational tests regarding the impulses of ground potential rise (GPR) to surge protective devices (SPD), and emphatically analyzed the impulse and damage effects of the initial long continuous current processes of triggered lightning on the SPDs. The results showed that after the triggered lightning currents were injected into grounding grids, the SPDs with rated flow rates were easily damaged under the joint actions of the initial long continuous currents of the lightning and the subsequent return strokes. It was observed that when the energy flowing through the SPDs had accumulated to a certain level, only the initial long continuous current processes had caused damages to the SPDs. The impulse effects on the SPDs were determined to be closely related to the different waveforms of the initial long continuous current processes. For example, when the long continuous current processes were superimposed by the initial continuous current pulses (ICCP), with fast rising edges and large amplitudes, then the energy passing through the SPDs tended to rapidly increase. This was believed to likely be the most critical factor related to the damages to the SPDs during the long continuous current processes.