A new design of substation grounding based on electrolytic cathodic protection and on transfer corrosion current

Abstract

In this paper, zinc material is used as auxiliary anode grounding electrode and connected by flat steel to form grounding grid of electrolytic cell protection circuit, to prevent the main grounding grid from corrosion. At the same time, the paper designs to transfer the lead-down from the grounding grid to the auxiliary anode grounding grid, and to transfer the corrosion current to the auxiliary anode grounding grid. Several groups of zinc-iron electrodes were deeply buried in deep excavated soil outdoors to conduct simulated grounding grid protection tests. At the same time, the software simulation is carried out in the laboratory. Firstly, Rotating Disk Electrode (RDE) and Solartron electrochemical interface were used to compare the current-voltage curves of three cases (natural anode, passive cathode and active cathode), and the corrosion rates of the three cases were calculated. Secondly, ATP-EMTP simulation software is used to simulate the point voltage and current of the auxiliary anode grounding grid before and after the design of the transfer corrosion current. The simulation results show that passive electrolytic cathode has better corrosion protection. The auxiliary anode grounding grid design and the transfer corrosion current design can better prevent the main grounding grid from corrosion.