Novel Method for Measuring the Grounding Resistance of Towers With Short Electrode Wire

Abstract

The three-electrode method is the most commonly used grounding resistance measurement method. But the electrode wire of the three-electrode method is too long to be used in mountainous areas or densely built areas. Therefore, it is of great application value to effectively shorten the electrode wire under the condition of ensuring measurement accuracy. In this article, a novel method for measuring the grounding resistance of towers with short electrode wire is proposed. Based on the connectivity of soil inside and outside the tower foundation, the limited space inside the tower foundation is fully used to arrange the electrodes. The principle of arranging electrodes inside the tower foundation to measure the grounding resistance is deduced in detail. The calculation method of the compensation point position and measurement error is studied. The best way of arranging electrodes is proposed. Through simulation experiments and field tests, we confirmed that the measurement accuracy of this novel method is similar to that of the three-electrode method. Its electrode wire length is shorter than the three-electrode method and other improved methods. Only the length of electrode wire needs to be the same as the length of the grounding conductor, and the measurement error can be controlled at about 3%. The novel grounding resistance measurement method has a wider application range and higher measurement efficiency.