Open AccessEvaluation principle and method of horizontal grounding electrode based on time‐varying impedance
Author(s) -
Cao Xiaobin,
Wei Ming,
Wang Manxiang,
Liu Jiacai,
Li Ruifang,
Yang Lin
Publication year - 2021
Publication title -
iet science, measurement and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.418
H-Index - 49
eISSN - 1751-8830
pISSN - 1751-8822
DOI - 10.1049/smt2.12019
Subject(s) - electrical impedance , impulse (physics) , damping factor , characteristic impedance , electrode , ground , output impedance , acoustics , impulse response , materials science , mechanics , electrical engineering , engineering , input impedance , physics , mathematics , mathematical analysis , quantum mechanics
The length of the horizontal grounding electrode is usually extended to decrease the impulse grounding resistance. In this paper, the mechanism for influencing the effective length is revealed by studying the dispersal process of a horizontal electrode and a method for determining the length is proposed. Firstly, the impulse current and the response voltage are measured at different positions. The results are used to analyse the time‐varying characteristics of the impedance in the dispersal process, the mechanism and the factors influencing the effective length. Furthermore, the current propagation process is divided into a wave head process and a wave tail process. The variation rule and influencing factors of the transient impedance are determined. The wave head impedance acts as a dynamic process from the injection impedance to the wave tail impedance, and the injection impedance is not affected by the length of the grounding electrode. The wave tail impedance is constant and is equal to the DC steady‐state impedance. It is proposed that the effective length is caused by two different dispersal processes and it is obtained when the tail impedance is equal to the impulse grounding resistance. These results are highly significant for optimizing the grounding device.