Long Term Performance of Silicon Based Composite Insulators

Completed

Other Power and Storage Technologies(Electricity transmission and distribution)

Applied Research and Development

PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials)
ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering)

Not Cross-cutting

Project Contact
National Grid Electricity Transmission

Network Innovation Allowance

Ofgem

01 October 2008

01 January 2014

65 months

£500,000

Power

London

Network Innovation Allowance

Project Contact, National Grid Electricity Transmission

The key objective is to advance understanding the aging mechanisms for polymeric / composite insulators. Completion of a report of the impact of asymmetrical ageing on insulator performance. Development of a model capable of calculating electrical stress on insulator structures including asymmetry Development of a stochastic tool suitable for asset management and investment decisions. Recommendation of a process for composite insulator management for GB TOs

Traditionally ceramic insulation has been used for all substation devices required to provide HV conductor to ground insulation clearance. Examples are CTs, VTs, Bushings and Post Insulators which use a special shed profile to optimise on size, strength, creepage and provide weather and pollution resilience. This technology is well proven, reliable, with a predictable life and has been used for over 50 years. However, although rare, these devices can fail catastrophically and unexpectedly. In addition they are heavy and susceptible to damage during manufacture, transport and installation phases and require larger civil foundations and structures to support them than those made from lighter materials. Polymeric insulation is now a viable alternative to ceramic insulation and there is growing adoption and experience in other utilities. However there are a number of choices on the market, particularly relating to material, shed profile and manufacturing processes. There is also uncertainty over the mechanical strength, proven life, maintenance needs and performance over time. This project seeks to address the relative paucity of information about the reliability and performance of silicone based insulators as they age. The current research has identified an additional phenomenon that may have an impact upon life-time performance of polymeric insulators asymmetric aging patterns. Evaluations of this along with the development of an asset management tool to predict performance of polymeric insulators throughout their life forms the basis of this proposal. Research Existing service aged insulators and artificially aged insulators will be subject to number of laboratory based electrical performance tests. Finite element analysis and complementary analytical techniques will be used to model aging processes and electrical performance. This will be used to forecast how aged insulators respond in extreme environments. A stochastic model of long term performance will be developed assess the impact of different assessment strategies on likely life to point of failure.Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above

31/08/18