A Study of Detecting the State of Grounding Conductor by Spectrum Analysis

Grounding system is an important part to protect the stable operation of power system and equipment safety. In the existing fault diagnosis and status assessment methods of grounding conductor, stoppage, power off or manual digging are often used. This paper presents a method of grounding conductor state detection based on spectrum analysis, which can detect the ground conductor state through the spectrum characteristics of ground impedance. Firstly, the simulation magnitudels of four common grounding conductors are established, and the phase-frequency and amplitude-frequency curves of grounding impedances of different grounding conductor structures are calculated. Secondly, the spectral response curves of grounding conductor length, equivalent radius and soil resistivity to impedance magnitude and impedance Angle of grounding impedance are analyzed. In this paper, it is found that the frequency response characteristic of ground impedance is feasible to detect the state of the grounding conductor.