Earthing Analysis of High Voltage Laboratory at NUST /

Abstract

Extensive use of electricity in all aspects of the industry and domestic daily life has resulted in the expansion of power systems with increased levels of generation and transmission voltages. Due to the presence of high voltage grid stations and transmission structures, high voltage engineering has emerged as the specialized branch of electrical engineering to deal with the research and development in this area. Several high voltage laboratories have been established worldwide and they have become a need to support the electrical power industry of the country. A high voltage laboratory in a university is a part of the theory and experimentation of electrical engineering courses as well as an integral part of the research proceedings in the domain of high voltage engineering and power systems. Keeping the needs in mind, a high voltage laboratory has been established at the U.S. Pakistan Center for Advanced Studies in Energy (USPCAS-E), National University of Sciences and Technology (NUST), Islamabad. In addition to many other parameters, an effective and reliable grounding system is necessary for the safety of equipment and personnel working in a high voltage laboratory. The study analyzes the performance of the grounding system of the high voltage laboratory. Field tests have been performed to analyze the parameters of the ground such as soil resistivity and ground resistance. Recorded data is used to model two grounding systems in ETAP software. These models are simulated for the calculation of safe limits of touch and step potentials in the high voltage laboratory. By using grounding system analysis techniques based on IEEE-80 standards, and programs based on soil-layer models, the grounding system of the high voltage laboratory is analyzed and solutions to the encountered issues are recommended.