Effect of the response of grounding systems on impulse current or vpltage is very important to power system over voltage, besides can affect the protective performance of the arresters. When surge current is high, the electrode system attains very high electric potential and field; both are affected by properties of soil, electrode size, and impulse. This paper describes the distribution of electric field and potential based on theory and simulation using Matlab around a grounding electrode under soil surface by cylindrical shape distribution approach. The variables are limited on size and length of electrodes, with other conditions are constant. The software has plotted the electric field and potential distributions based on dinite element method (fem). In general, the electric potential distribution show the contour in the same pattern for different physical condition, but there is a different pattern between impulse voltage and impilse current effects. The result of the greatest electric field contour distribution occur on the end of the electrode that shown by the level of contour density. Keywords: Electrode of single rod, electric field and potential distribution, electric potential distribution, impulse voltage and current, contour, finite element method. Waluyo; UIKA Bogor.
