Study On The Corrosion Analysis And Reconstruction Of Substation Grounding Grid

The stability of the substations could affect the safety and reliability of power grid and power transmission equipments.As an important part of substation,the corrosion resistance of grounding grid plays a very important role for the stable operation of substations.The operation of power system shows that the earthing resistance would rise and the grounded conductor corrosion would be decomposed in many substations while its designed working life is not reached.Solving the corrosion problem of grounding grid and prolonging the service life of grounding grid would be an important guarantee for the stable operation of substation and the safety production and operation of power transmission and transformation.In this paper,we have taken the grounding grid of a 220 k V substation in Nanjing Power Grid Corp as an example and focused on experimental study for the effects of conductive anti-corrosion coating on the corrosion resistance of Q235 carbon steel used in substation grounding grid.Based on the experimental research,the transformation work of anti-corrosion and resistance reduction has been studied in this paper to solve two problems appeared in the substation grounding grid: serious corrosion and high rarthing resistance,which are both affecting the safe operation of the power grid:(1)The effect of the conductive coating on the corrosion resistance of Q235 carbon steel in the grounding grid of the substation is studied by means of the conductive properties of the coating and the accelerated simulation experiments.The experimental results show that the corrosion resistant coating has good stability,which could inhibit the corrosion of Q235 carbon steel in the soil layer effectively,and has good electrical conductivity meanwhile.(2)In addition,aiming at the problems existing in the grounding grid of the 220 kV substation the application of conductive anti-corrosion coating for corrosion and resistance reduction is studied from the aspects of structure,parameter and construction of substation grounding grid.The application effect of the project is very good: the earthing resistance of grounding grid is reduced at the same time to guarantee its corrosion resistance.