The Application of Bacfills for Improving the Grounding Resistance of Power Systems

Abstract

This paper describes monthly field results obtained for several electrodes installed and tested at an experimental field with a high resistivity soil feature. Several chemical backfills were also used in order to determine which of them could improve the grounding connection and then compared to a driven rod without any backfill. It is also shown the main variation of the grounding resistance for every kind of electrode which includes its comparison among them as well the determination of the lowest grounding resistance of each electrode. Main backfills' application is on grounding power substations as well as grounding transmission lines, where lightning strokes may cause many problems, mainly on high incidence areas, where as a consequence, overvoltages at the top of the towers are raised up to high values, increasing the risk of failures and causing backflashovers on the line insulation because of the presence of high grounding resistance connections