| The good conductivity of the grounding system is the prerequisite for ensuring the safe operation of power lines.Based on the excellent electrical conductivity and corrosion resistance of graphite,products made of graphite have been widely used in grounded radiation networks,but the main part of the grounding down conductor of the grounding system is still a metal material.In the actual operating environment,when the galvanic corrosion of the material at the connection occurs,the metal material will be corroded.The corrosion rate of metal materials in different soil media is different.How to choose the appropriate metal material as a grounding conductor in different use environments to extend the service life of the metal material,reduce the frequency of replacement,and how to choose a new material Reducing the voltage difference between the materials at the joints and delaying the tendency of the materials at the joints to corrode are the main content of this study.In this paper,the optimal choice of metal materials in different soil environments is first studied.The research method is to add distilled water,Cl-,and SO42-to the basic soil to study the influence of these factors on the corrosion rate of the material.According to the test results,in soil media with different water contents,the maximum corrosion current density of galvanized steel is 20.61?A·cm-2,the maximum corrosion current density of 304 stainless steel is 0.83?A·cm-2,and the maximum corrosion of copper metal The current density is 1.88?A·cm-2.In the soil medium containing Cl-,the maximum corrosion current density of galvanized steel is 129.52?A·cm-2,the maximum corrosion current density of 304 stainless steel is 2.12?A·cm-2,and the maximum corrosion current density of copper metal is 11.89?A·cm-2.In the soil medium containing SO42-,the maximum corrosion current density of galvanized steel is 64.86?A·cm-2,the maximum corrosion current density of 304 stainless steel is1.12?A·cm-2,and the maximum corrosion current density of copper metal is 5.92?A·cm-2.Therefore,in soil media with a high water content,all three metal materials can be used for grounding down conductors.In the soil medium containing more Cl-,304stainless steel should be used as the ground lead.In the soil medium containing more SO42-,copper metal and 304 stainless steel can be used as the grounding down conductor.Then,the performance test of the armored graphite tape was carried out,and the obtained results proved the feasibility of the armored graphite tape used as grounding down conductor.The judging standard is the change of DC resistance,connection resistance and quality of the armored graphite tape after related tests.First of all,this paper shows that the optimal expansion temperature for preparing graphite worms in engineering should be set to 800?through the expansion temperature test.Secondly,the physical property test proves the stability of the physical structure of the armored graphite tape.The electrical performance test proves the impact stability of the armored graphite tape.Finally,the influence of the external environment on the armored graphite tape is studied,and a conventional method for reducing the influence is proposed.According to the above test results,the feasibility of using armored graphite tape as grounding down conductor is proved. |
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