Simulation calculation of impulse grounding resistance of 10 kV distribution line, Part 3: methods comparison and device development

The reliable grounding of equipment in power systems is the key to ensuring the safe operation of equipment. The grounding resistance of grounding devices, especially the impulse grounding resistance, determines the overvoltage protection of equipment and the lightning protection of transmission and distribution lines. The impulse grounding resistance of a grounding device is related to many factors such as its structure size, soil resistivity, lightning current parameters, and buried depth of the device. Therefore, it is practical to study the calculation method and measurement technology of impulse grounding resistance. In this paper, the definition of impulse grounding resistance, difference between impulse grounding resistance and conventional power frequency grounding resistance, and its practical significance in engineering are briefly analyzed. In addition, an impulse grounding resistance testing technology based on small multi-waveform signals is proposed, and an impulse grounding resistance testing device that can meet the engineering application needs is developed.