The Research Of Detecting The Tower Grounding Corrosion

Running transmission line tower grounding grid related to the safety of transmission lines as well as the grid,As the tower is generally in the field,the distribution range is wide and the running environment is bad,and the grounding body is prone to corrode.Therefore,the corrosion problem of the tower grounding body is always troubling Power Department.Traditionally,To determine the corrosion of the tower ground is usually used Large area excavation and measuring power frequency grounding resistance.This method is not only inaccurate,but also time-consuming and laborious.Therefore,it is very important to study the corrosion detection method of the tower grounding body,which is of great significance to ensure the safe operation of the transmission line.There are many researches on the method of corrosion detection of rod grounding.Grounding body corrosion not only reduces the conductor cross-section caused by the conductor resistance,inductance changes,and corrosion of the impact of bulk and capacitance changes.But for the tower,the location and extent of corrosion will eventually be reflected in the impact of the ground impedance changes,the impact of ground impedance measurement method is by injecting the simulation of the impact current,measuring the impact of the tower grounding impedance to determine whether there is corrose.In order to analyze the influence of the corrosion of the grounding body on the impact impedance,the mathematical model of the distribution parameters(inductance,resistance,capacitance and conductance)of the tower grounding body at low frequency and high frequency is established.Since the injected impulse current amplitude is not large,the model does not need to consider the spark effect.The relationship between the distribution parameters of the grounding body and the geometrical shape of the grounding body is calculated by MATLAB simulation software,and the variation law of the impact grounding resistance under different corrosion conditions of the tower grounding body is calculated.At the same time,the equivalent model of grounding is used to construct the grounding body,and the impact characteristics of the grounding body are analyzed.Based on the analysis of various factors influencing the perceptual component of ground impedance,the conclusion that the inductive component increases with the deepening of corrosion at high frequency is obtained.Based on the measurement principle of impulse grounding impedance,this paper uses the amplitude of the smaller impulse current to simulate the lightning current as the test current.The collected signal is subjected to time domain-frequency domain transformation,In the frequency domain,Calculating the impact of the ground impedance.isolated resistive and emotional components.then devising the corrosion detection system,its simulation experiments and analysis of the measured data to prove that the system is feasible.Finally,the experimental results show that the corrosion of the tower grounding body has a great relationship with the impact grounding impedance.The conclusion of the study provides the theoretical basis and practical reference for the corrosion state detection of the tower grounding body.