ANALISA KEBUTUHAN PERLINDUNGAN KATODIK UNTUK SISTEM PENTANAHAN PERALATAN TIPE GRID-ROD BERBAHAN BAJA PADA GARDU INDUK

Abstract

One of the most important thing in the substation is operator and equipment safety when a high fault current occur . A grounding system should be installed in a manner that will minimize effect of ground potential gradients to such voltage and current levels that will not endanger the safety of the people or equipment under normal and fault conditions. System of ground electrodes has the form of a grid as horizontally buried conductor, supplemented by a number of vertical ground rods connected to the grid. Commonly, Copper is used as primary ground conductor material, however Steel may also used for ground grid conductors and rods. Of course, such a design requires that attention be paid to the corrosion of the steel. Use of galvanized or corrosion resistant steel, in combination with cathodic protection system, is typical for steel grounding systems. A simulation programme will be used in this final project. This programme used for simulating cathodic protection system design calculation for substation steel grounding system. The simulation result are appropriate design parameters of sacrificial anodes cathodic protection system for substation steel grounding system. The simulation Programs will be created using GUI design environment (GUIDE) tools with Matlab 7.9 programming. The results of the experiments described that an appropriate sacrificial anodes cathodic protection system is needed for protecting steel grounding system from corrosion. Magnesium anodes and zinc anodes can be used for sacrificial anodes, however, only certain sizes magnesium anodes can be used in this case. At least 5645,2138 lb magnesium anode is needed to protecting steel grounding structure for 20 years. In this case, A 17 lb magnesium anode with 6” 55”packaged size is selected to be used. Based on the prices comparison, 60% savings can be achieved in some cathodicaly protected substation steel grounding design. Keywords : Steel Grounding, Corrosion, Cathodic Protection, Magnesium Anode, and Zinc Anode.