Анализ результатов натурных импульсных испытаний стержневого заземлителя

Abstract

The results of field tests of the grounding rod practically coincide with the calculation to the previously derived formula. The reason for the decrease in impulse resistance is shown – more intense sparking due to the decrease in critical strength at the boundary of the sparking zone. It was proved by calculation that at current of 100 kA with an increase in the length of the rod, an increase in the pulse resistance, and therefore it is impractical to increase the size of ground electrodes. Since the obtained values of the impulse resistances are much less than those on which the operating power lines are built, the impulse resistance cannot be the reason for the disconnection of the line. It is necessary to look for other reasons for the insufficient of overhead lines. In the Rules for Electrical Installations (PUE), not the specific soil resistances, but the calculated impulse resistances of the grounding of the power transmission line supports should be indicated. In the Rules for the Installation of Electrical Installations (PUE), should be not indicated the specific soil resistances, but the calculated impulse resistances of the grounding of the power transmission line supports.