Research On Anti-corrosion Coating Of Transmission Line Grounding Device

Substation grounding grid and overhead line grounding body are important facilities to ensure the safe and stable operation of the power system and the personal safety of the inspection personnel.In the case of corrosion defects in the grounding device,the shortcircuit current or lightning impulse current cannot be effectively diffused to the far side of the earth through the grounding grid or the grounding body,resulting in an increase in the ground potential and a step potential difference near the grounding device.It endangers the personal safety of the inspection personnel,penetrates the insulation of the secondary protection device,and even damages the equipment,expands the accident,and damages the stability of the power grid system.In recent years,there have been a lot of researches on the corrosion behavior and diagnosis of grounding grids in China,but there are few applications for the development of new protective coatings and corrosion protection for grounding devices.In order to improve the anti-corrosion performance of the grounding device,the subject uses a thermal spraying method to increase the cermet material coating on the surface of the grounding conductor,thereby improving the corrosion resistance and operating life of the substation grounding grid and the overhead line grounding body.In order to improve the anti-corrosion performance of the grounding device,the method of supersonic flame spraying is used to increase the coating of Ni Cr and Ni60 cermet materials on the surface of the grounding conductor,so as to improve the anticorrosion performance and operating life of the substation grounding grid and the grounding line of the overhead line.In order to improve the anti-corrosion performance of the grounding device,the method of supersonic flame spraying is used to increase the coating of Ni Cr and Ni60 cermet materials on the surface of the grounding conductor,so as to improve the anticorrosion performance and operating life of the substation grounding grid and the grounding line of the overhead line.main tasks as follows:(1)Using a supersonic flame spraying technique to prepare two different materials(Ni Cr and Ni60),five spray coating layers(3,5,7,9 and 11)and a cermet coating on the surface of the sealant.Introduce the main equipment of supersonic flame spraying and its preparation process.The electrical properties of the coatings of various parameters were analyzed by four-stage method,contact resistance method and CDEGS simulation software.Results Surface: The two cermet coatings prepared by supersonic flame spraying have no sealing agent on the surface of the coating,and the electrical properties of the coating are less than 11 layers,which can meet the requirements of the grounding system of the power system.(2)The corrosion resistance of the coating was analyzed by neutral salt spray corrosion test.The results show that the surface of Ni Cr cermet coating,galvanized steel and Q235 steel is severely corroded in the coating without sealing agent.Corrosion effect is poor,and when the number of sprayed layers of Ni60 cermet coating is more than 5 layers,although the surface is partially rusted,most of the coatings are not rusted;and the coating coated with sealing agent has the most corrosion resistance.Well,only a small amount of pitting occurs in the salt spray corrosion test.It is proved that the Ni60 cermet coating can effectively improve the rust resistance of the substrate,and the Ni Cr coating can only improve the corrosion resistance of the substrate when the surface is coated with a sealing agent.(3)By comparing the corrosion resistance and electrical properties of the coating,it was found that the electrical properties of the coating coated with the sealing agent could not meet the requirements;in the coating without the sealing agent,Ni60-7-2,Ni60 The corrosion resistance of-9-2 and Ni60-11-2 meets the requirements and the electrical performance is good.(4)When Ni60 cermet coating prepared by supersonic flame spraying method,when the powder feeding voltage is 5V and the number of spraying layers is 7 or 9 layers,the surface of the coating is uniform,the porosity is low,the thickness is uniform,and the resistance is uniform.Corrosion effect is good,it is the best setting.