Simulation Research And Experimental Analysis About Electric Field Of Cold Water System In Converter Valve

China's current UHV AC-DC technology is already at the world's leading level.China has established a large number of(special)HVDC transmission projects.The converter station is the hub of the DC transmission project,which plays an important role in energy conversion and transmission.As the core equipment in the converter station of the DC transmission project,the converter valve has the functions of AC/DC conversion and power transmission,which is of great significance to ensure its safe and stable operation.The valve cooling system is one of the important systems to ensure the operation of the converter valve.It is known from the existing operation data of the converter station that the water leakage in the cold water system of the valve tower will cause a serious problem,and the safety operation of the converter valve will be greatly hidden.In order to suppress electrolytic corrosion,a certain number of grading electrodes are disposed in the entire water path,so that the water path forms an equipotential path to reduce corrosion caused by leakage current.Based on the scientific and technological project of China Southern Power Grid Co.,Ltd.,the high-voltage transmission company of China Southern Power Grid Co.,Ltd.,based on the water leakage damage of the cooling water pipe at the Converter Station,the potential distribution of the grading electrode and the cold water circuit was studied:1.Introduce the key components and abnormal treatment of the Converter Station.The emphasis is on the appearance structure of the grading electrode and the distribution position and function in the cold water circuit.Two typical accidents related to the grading electrode.2.Modeling the valve tower and cooling waterway of the Converter Station,determine the boundary conditions of the electric field simulation based on the relevant electrical connections,and analyzing the potential distribution of the cooling water circuit under different working conditions,and at different voltages.The discharge of the cooling water pipe was verified by the grading electrode line.The cause of the fouling of the grading electrode was analyzed by electric field simulation.3.The electric field strength of the grading electrode line and the cooling water pipe at different distances were analyzed,and the simulation experiment was carried out according to the simulated boundary conditions.It was observed by the ultraviolet imager that the distance between the two was significantly increased,which is also In this paper,the reasons for the damage of the converter station are discussed: The distance between the equalizing electrode line and the cooling water pipe is too close to cause corona damage.