Contribution of polymers to classical primary insulation of distribution system

Insulation composites used on present distribution lines frequently consist of several types of materials such as wood, porcelain, polymers and fiberglass reinforced plastics (FRP) connected in series. A study, which included the laboratory determination of the critical flashover voltage (CFO) of 17 single component and 90 combinations of two components, was conducted. The acquired data were used to develop methods of predicting CFO levels of various multiple series electrical insulations. This paper illustrates the results and analyses of classical primary insulation (porcelain), and of modern-day polymer insulation. It also presents the results of whether polymers may add or supplement the insulation strength to the two dielectric combination, analyzed using statistical methods. The paper also presents advantages and guidelines for the use of polymers to either replace or complement porcelain. This may help optimize the choice of dielectrics on distribution lines