Research On Grounding Grid Corrosion Diagnosis Of Substation Based On Magnetic Induction

It plays an important role for the perfect substation grounding system to ensure the safety of the operators in the station and ensure the normal running of electrical equipment.Nowadays,with the developed rapidly of the power grid and the increased constantly of the voltage level,it has become a reality to build the substation grounding grid with high voltage and large volume.In case the ground fault occurs,it will produce a huge fault current,which means it have to put forward higher requirements on the performance of the grounding grid.To obtain the parameters by measuring the grounding grid,and then make the correct judgment and corresponding maintenance of the grounding grid corrosion.In this way,it not only can avoid the excavation soil to find the corrosion conductor,to a certain extent,but also it can save manpower and material resources,prevent and eliminate hidden dangers in time.Therefore,studying grounding grid corrosion diagnosis method play a very significant role in maintaining the operation of electric power system safety.Aiming to the substation grounding grid corrosion problem,this paper makes a detailed analysis and research.On the basis of electromagnetic induction principle,the paper analyzes the distribution characteristics of the surface magnetic flux density under the perfect grounding grid and conductor corrosion,and study s the influence of three kinds of factors,such as the mu-til layer oil,the frequency of driving current and the extraction mode of driving current on the distribution of magnetic induction intensity.On this foundation,the corrosion location of conductor is determined by calculating the corrosion distance vector between the surface magnetic induction above the grounding grid conductor.According to the distribution rule of the surface magnetic induction,the paper is put forward the diagnostic method of the grounding grid conductor corrosion degree.It is feasible of this method by a large number of instance simulation and field experimentation.Under the condition of without excavation and no effect of the substation normal operation,we can diagnose the conductor's corrosion location and the corrosion state.