A New Approach for Monitoring Grounding Grid of Electrical Power System

A new approach, to monitor the corrosion status of the grounding grid which plays an important role in the power system, is proposed in this paper. This method is based on the principle of potentiostatic technique, by which status of grounding grid can be detected from the sensor buried in earth near the grounding conductors. The mathematical relationship among corrosion depth, the measured soil resistances and corrosion potential is deduced in detail based on circuit model and theory. The integral quantity of corrosion depth in a year is the yearly corrosion depth. The status of grounding grid can be known from this yearly corrosion depth. This new approach has been tested in laboratory and in Yanfeng substation in China. The test reports demonstrated that the proposed model is a practical tool to monitor the status of grounding grid.