Research Of Corrosion Degree Of The Grounding Grid Identification By Transient Electromagnetic Method Based On Improved LeNet-5 Network

As an important protective structure in power system,the grounding grid is welded by metal conductors to ensure the potential stability of equipment connected to the ground grid.The grounding grid conductors in China is made of the common flat steel materials,which needs to be buried in the ground during the service process.Under the complex soil environment,the grounding grid conductors will continue to suffer from electrochemical corrosion,the cross-sectional area of the grounding grid conductor will decrease,and the thermal stability of the conductor will be reduced.As a result,the grounding performance of the grounding grid will be weakened,which cannot meets the requirements of normal operation,threatening the stable operation of the power system.It is the main method that detect and analyze the data of the grounding grid to evaluate the corrosion degree of the grounding grid.There are various detection methods,among which the transient electromagnetic method can ensure the complete electromagnetic response data of the grounding grid without excavation.On this basis,by improving LeNet-5 network,this paper identifies the electromagnetic response data induced by the grounding grid with different degrees of corrosion,and proposes the transient electromagnetic method based on the improved LeNet-5 network to identify the corrosion degree of the grounding grid,mainly in the following aspects:1.Based on transient electromagnetic method,the calculation of mutual inductance between the grounding grid and circular plane,square plane and composite plane is derived,and the electromagnetic response data of the grounding grid is obtained by using transient electromagnetic method.2.Based on the theory of convolutional neural network,the error expression and weight update formula are derived,and the theoretical basis of intelligent algorithm is established.3.On the basis of simulation,the electromagnetic response data of the grounding grid are studied in terms of topological structure,corrosion position and corrosion degree,and the data sample base of the grounding grid’ corrosion degree is gradually established,which contains 40,000 pieces of the grounding grid’ electromagnetic response data of different corrosion degrees,providing data support for network identification.4.The method was proposed that identify corrosion degree of the grounding grid by transient electromagnetic method based on improved LeNet-5 network.The Lenet-5 network was established by simulation.The optimal network parameters are obtained by testing the batch size,learning rate and activation function of the network.5.Adopting the experimental model of the corrosion degree of the grounding grid,this paper gets the electromagnetic response of the experimental model of the corrosion degree of the grounding grid by transient electromagnetic detection equipment,and then use the software to process the detection data,and finally input it into the improved LeNet-5 network which is saved for verification.The feasibility of the identification method of corrosion degree of the grounding grid identification by transient electromagnetic method based on improved LeNet-5 network is verified.The results show that the network can be used to identify the corrosion location of the grounding grid and the corrosion degree of the conductor at the corrosion location,which provides a new method for identifying the corrosion degree of the grounding grid.