Study on Dissipation Characteristics of Grounding Electrodes for Transmission Line Towers Under Continuous Impulse

Under continuous lightning impulse conditions, the impulse dissipation characteristics of grounding electrodes significantly differ from those under single lightning strike conditions and more accurately reflect the lightning protection effectiveness of transmission line tower grounding. To further investigate this characteristic, this study constructed a continuous impulse simulation experimental platform. Grounding electrodes of different materials, shapes, and diameters were selected for continuous impulse experiments, and the primary and secondary impulse grounding resistances and soil recovery coefficients of the grounding electrodes under different conditions were compared and analyzed. The results show that the material type and shape of the grounding electrodes significantly affect their continuous impulse dissipation performance. Specifically, manganese copper material and cross-shaped grounding electrodes exhibit superior continuous impulse dissipation characteristics. The diameter of the grounding electrode material has a saturating effect on optimizing its impulse dissipation characteristics. Notably, manganese copper grounding electrodes with diameters of 10 mm and 15 mm show similar continuous impulse dissipation performance. Therefore, in the design of tower grounding, the material and shape of the grounding electrodes should be comprehensively considered. The research findings of this study are expected to provide theoretical references for the design of grounding electrodes in transmission lines.