Optimal design and development of software for design of substation grounding system

Role of substation is crucial in overall functionality of power system. In any substation, grounding system deserves considerable attention as far as performance and design are considered. Design of an effective grounding system is of very much importance because it deals with personnel safety and also operation and protection of equipments. Main purpose of this work is development of software ‘Optimal Ground Grid Designer’ which gives safe and optimum design of substation grounding system. This software has been designed using MATLAB as a mathematical tool. Methodology adopted for designing the grounding grid is as per IEEE standard 80–2000. Moreover this program also allows two layered soil modeling which is not given in IEEE guide. This program allows simple analysis of grounding system performance for given data and is able to recommend optimal design of the grounding system in the given conditions and safety constraints. A Design problem of grounding system design of 400 kV ASOJ (Gujarat) substation has been solved using this software. Results obtained here are also compared with those obtained by using ‘Ground Grid Systems’ module of ETAP. A close agreement is observed between the results obtained by both softwares. Hence the software developed herein effectively gives optimal design of substation grounding system in terms of cost effectiveness as well as safety for various grid geometries.