Abstract
High values and uneven distribution of the transient ground potential rise (TGPR) at grounding grid conductors in cases of lightning can disrupt the system safety and reliability. To assess the transient performance of grounding grids under lightning currents, a parametric analysis was performed with a computer simulation of 13,978 cases of time-domain responses with a broad range of parameters. From this study, graphs of impulse impedance and a new formula for the effective area have been developed. The graphs are general, describe grids of any shape and size and depend on three parameters: grid conductor spacing, the resistivity of earth, and the zero-to-peak time of the lightning current pulse. Although the parametric analysis was based on a uniform soil model, the graphs can also be used for the two-layer soil model. In this paper, graphs and formula are used in a simple procedure to estimate the effectiveness of a mitigation measure to reduce the TGPR by increasing the grounding grid mesh density in a limited area around the current injection points. The results from the procedure are compared with experimental results, and the application and limitations of the procedure are illustrated by considering large grounding grids as examples.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
