Design of a Grounding Grid Corrosion Detection Device Based on the Electrical Network Method

Abstract

Grounding grids are prone to corrosion after a period of operation, which endangers the safety of production on site. Therefore, periodic inspection of the integrity of grounding grids is very important to ensuring safe production. Electric network theory is a method of introducing the parameter identification method used in analog circuit fault identification into the evaluation of grounding grid corrosion. Based on the measurement principle of electrical network theory, we design a corrosion detection device and the corresponding measurement method for the grounding grid. The device is designed with 16 channels, and up to 16 grounding grid accessible nodes can be connected at the same time. The system controls the conduction of any two channels through a matrix switch to form a detection port and adopts a rotation of the excitation source to inject excitation signals into the network ports in turn and detect the output response. The matrix switch adopts the working mode based on the four-terminal electrode method. Using the strategy of partition measurement and multiple approximation measurements, the locations of the corrosion faults are determined. Finally, a laboratory simulation test is performed on the grounding grid corrosion detection device, and a field experiment is carried out at the Renzhuang Substation in Xuzhou City, Jiangsu Province, China. Through corrosion detection and diagnosis of the grounding grid of the Renzhuang Substation, the engineering application value and reliability of the grounding grid corrosion detection device are proven.