An Analysis of the Post-Flooding Resistance of the Ground Electrodes of the 22 kV and the 115 kV Power Distribution Systems in Pathum Thani Province

Abstract

Power system disruptions can stem from several types of natural disasters, including the rains, thunderstorms, and most notably flood. The objective of the present study is to examine the effects of flood on the resistance of the ground electrodes and the specific earth resistance of the 22 kV and the 115 kV power distribution systems in Pathum Thani, one of the provinces of Thailand most highly susceptible to flooding. The data were collected from five districts in Pathum Thani province, namely Bang Kradi, Khlong Luang, Rangsit, Lad Lum Kaeo, and Thanyaburi, using a systematic sampling technique. The research results are as follows. First, the post-flooding resistance of the ground electrodes of the 22kV power distribution systems was the highest in Thanyaburi district with the value exceeding the predetermined standard. Second, the post-flooding resistance of the ground electrodes of the 115 kV power distribution systems did not differ significantly from the predetermined standard. Finally, from an analysis of the specific earth resistance, the most suitable type of grounding for the 22 kV power distribution systems would be GR-1 for Bang Kradi and Khlong Luang districts and GR-2 for Rangsit, Lad Lum Kaeo, and Thanyaburi districts. In contrast, the most suitable type of grounding for the 115 kV power distribution systems would be GR-1 across all the districts. Based on the findings, it can thus be concluded that flood seems to have small effects on the resistance of the ground electrodes and the specific earth resistance of the power distribution systems in Pathum Thani province.

Keywords: flooding, resistance, specific earth resistance, ground electrode, power distribution systems.