What polymers and fiberglass reinforced plastics (FRP) may add to classical primary insulation of distribution system construction for withstanding lightning critical flashover voltages (CFO)

Insulation composites used on present-day distribution lines frequently consist of two or more types of materials such as wood, porcelain, polymers and fiberglass reinforced plastics (FRP) connected in series. A study included the laboratory determination of the critical flashover voltage (CFO) of 17 single component, 90 combinations of 2 component and 80 combinations of 3 component, and 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 the classical primary insulation (porcelain), and of the modern-day insulation of polymers or FRP. It also presents results of whether these newly emerged FRP and polymers may add or supplement insulation strength to the two and three dielectrics combination. The paper also presents advantages and guidelines for the use of polymers and FRP to either replace or complement porcelain. This may help optimize the choice of dielectrics on distribution lines