Progress in Lightning Impulse Characteristics of Grounding Electrodes With Soil Ionization

Grounding is the fundamental measure of lightning protection for power systems, industries, and buildings, and the lightning impulse behavior of grounding electrodes plays a very important role. How to correctly consider the lightning impulse characteristics of grounding electrodes is the fundament in lightning protection design. This paper summarized the progress in lightning impulse characteristics of grounding electrodes with soil ionization, including the images of soil ionization, the residual resistivity of ionized soil, the critical breakdown electrical field, the impulse breakdown delay characteristics of soil, and the impulse breakdown mechanism of soil. Finally, the numerical simulation methods for lightning impulse characteristics of grounding electrodes are classified, and some key performances of grounding electrodes under lightning impulse were presented.