학술논문
Evaluating the Impacts of Grounding Systems on Ground Currents and Transient Overvoltage
Document Type
Periodical
Author
Source
IEEE Transactions on Industry Applications IEEE Trans. on Ind. Applicat. Industry Applications, IEEE Transactions on. 58(5):6002-6013 Jan, 2022
Subject
Language
ISSN
0093-9994
1939-9367
1939-9367
Abstract
This article presents a performance comparison of the solid, low impedance, high impedance, frequency-selective, and isolated grounding systems. A grounding system (for any power system component) is designed as an impedance ($\bar{Z}_{G}$) that connects the neutral point to the ground. The impedance $\bar{Z}_{G}$ is constructed using a combination of $R$, $L$, and $C$ elements. The values and combination type (series or parallel) of $R$, $L$, and $C$ determine the possible influence of $\bar{Z}_{G}$ on ground currents and potentials. Each grounding system is related to a system voltages level, a specific combination of $R$, $L$, and $C$, and a range of $R$, $L$, and $C$ values. The solid, low impedance, high impedance, frequency-selective, and isolated grounding systems are designed for a $3\phi$ transformer and a $3\phi$ synchronous generator in order to compare their influences on ground currents and potentials during ground faults. The transformer and generator are tested for line-to-ground and double line-to-ground faults with all designed grounding systems. Test results show that some grounding systems can reduce ground currents only, while others can reduce ground potentials only. Such capabilities can be used to fulfill certain system and operation requirements (e.g., service continuity, ground capacity, etc.).