Analysis of IVAT laboratory grounding system using CDEGS software

Abstract

Practical tests on grounding systems has proved very costly and pose hazards on operating personnel. Therefore, numerical methods using computers provide the m ost appropriate tool to assess the earthing systems. The research has been conducted with the utilization o f CDEGS software as a tool to simulate all necessary phenomena on the built CDEGS model o f the grounding system in IV A T’s laboratory. In particular, the ground potential rise, touch voltages, and step voltages plots are the main outputs generated. Six lightning scenarious catergorized into low, medium and hight levels are applied on the proposed grounding system to assess for the IVAT’s earthing structure safety. The IEEE 80-2000 standard is used to calculate the maximum allowable limits for surface potentials and employed as set point. Obtained results were compared to the safety lim it of the standard and proved safe only for the low level when no protective layer is in use. However, the system was completely safe and m et the standard’s limits for low, medium and high levels of lightning strikes when a protective layer is in place.