Surface Charge Properties of Epoxy Composites under DC Voltage Affected by Surface and Bulk Conductivity

As DC transmission voltage increases, the wall bushing becomes longer, and a supporting insulator is introduced to keep conductor straight. Under extremely high electric fields coupled with thermal gradient, surface charge of may distort field distribution increase risk flashover. In this paper, potentials three model epoxy resin composites were systematically investigated under varied amplitudes, different polarities distributions. The bulk resistivity over broad temperature range measured reveal correlations between such basic electrical parameters. results indicate that normal-dominated plays major role in accumulation. processes accumulation dissipation are more closely related resistivity. result, properties can be improved by optimizing electrode structure composites.