Comparison of conventional methodology and software CYMGRD when designing grounding systems of typical distribution transformer stations

Abstract

Design of the grounding system of power system facilities largely depends on the soil composition and its electrical characteristics, voltage level, dimensions of the object and other factors. This paper presents two calculation procedures intended for the design of the grounding system of a typical distribution transformer station. The first one, frequently used by the designers in Serbia, is based on the application of simple empirical formulas and diagrams, relying on the regulations, national standards and technical recommendations. The second calculation approach is represented by the use of a specialized software, based on modern mathematical methods, the results of which are verified using valid international standards. A comparative analysis of the results obtained using both methodologies, as well as the opportunities they provide to the designer, are presented. Both methodologies can be used when designing new grounding systems, as well as when reconstructing or maintaining the existing ones.