Design of a Substation Grounding System for Fast Front Overvoltage

Abstract

Grounding studies allow an optimized design of grounding system to provide protection for electrical components and personnel at substation. The design of grounding system needs to comply with IEEE Standard 80:2013. Field work is conducted with Fall-of-Potential method and Wenner’s method to perform measurement soil test. Data from measurement test is used to develop two-layer soil model by using Sunde’s graphical method. Calculation for tolerable step voltage and touch voltage are under 50kg body weight condition. Based on the findings, calculated values for tolerable step voltage and touch voltage are higher than calculated values for mesh voltage and touch voltage. The percentage of error is 7% when computed values and calculated values for tolerable voltages are compared. Higher tolerable voltages minimise the risk of getting electrical shock to any individual presents at substation during fault or lightning strike occurs. However, there is limitation in this paper related to software licensing where full simulation with grounding software required full access.