This publication analyzes the problem of the coupling of lightning and the power transformer in the High Voltage substations of electrical networks during the injection of lightning current to the ground in sites with strong thunderstorm activity, in this case the Democratic Republic of the Congo.Although the aggressive overvoltage induced by lightning is short-lived, its amplitude and frequency greatly disturb the stability in terms of voltage and the continuity of service of the network, especially in its transport part often exposed to open air.During the flow of this shock wave to the earth, through the protection devices (surge arrester) and the earth network, the transient impedance of the substation earth electrode varies suddenly depending on the amplitude of the current flow and the nature of the ground, and reveals around it a potential difference called step voltage and touch voltage, due to the distribution of the electric field, which expose the direct environment of the substation to the danger of electrocution and substation equipment against overvoltage.This publication aims to synthesize the corrector (regulator) which will have to dampen and reject the shock of the flowing current and prevent the potential difference around the earth electrode from reaching deadly values ​​for operators and people residing in the environment close to the substation and facilitated flow through the earth electrode.