Electrical Performance Analysis of Grading Electrodes After Scaling in Converter Valves

Abstract

Abstract It is necessary to take out the electrode when detecting the scaling degree of the conventional grading electrode. The steps are cumbersome and there are safety risks. In this paper, through the analysis of the equivalent circuit model before and after the scaling of the grading electrode on the cooling water manifold in the converter valve, the loop resistance model suitable for the positive and negative potential sides is obtained. The constant voltage DC source is used as the driving voltage of the circuit, and the leakage current of the circuit is measured under different temperatures and conductivity conditions of the internal cooling water. The degree of scaling of the grading electrode is determined by analyzing the leakage current. The leakage current in the non-scaling state of the grading electrode and the leakage current in the scaling failure state of the grading electrode are taken as the reference values. It is concluded that when the leakage current of the measurement circuit decreases to 68 % - 80 % of the leakage current in the non-scaling state of the grading electrode, the grading electrode can be considered to fail.