World-wide long-term outdoor performance of polymer concrete insulation

Abstract

Polymer concrete is a composite material that has been developed to be a technically and economically viable alternative to porcelain for a wide variety of both indoor and outdoor applications. Polymer concrete high voltage insulation is now seeing outdoor application in distribution systems in Brazil, the USA, the UK, Australia, etc. While most applications are in the form of post insulators serving as bus supports, applications in transformer and capacitor bushings, fuse cut-outs, C/V monitoring devices, retrofitted insulating cross-arms, etc., are steadily beginning to emerge. Based on the progress already made, polymer concrete is the most promising, versatile, and economically practical insulation system for the 21st century. This paper reviews the performance of various types of polymer concrete insulation systems in the field over 17 years, and discusses the lessons learned regarding their performance and durability, and opportunities for further improvement. Reference is made to the comprehensive field evaluation studies carried out under the auspices of an Electric Power Research Institute (EPRI-USA) project pertaining to 69 kV station post insulators made with various polymer concrete materials and incorporating different insulator designs. The advantages of polymer concrete insulators and integral polymer concrete structures in seismic areas are also briefly discussed in the context of the trouble-free, long-term performance requirements stipulated for high voltage insulation in electric power systems. >