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Projects: Projects for Investigator
Reference Number NIA_NGTO010
Title Liquids for cable sealing ends (LiCaSE)
Status Completed
Energy Categories Other Power and Storage Technologies(Electricity transmission and distribution) 100%;
Research Types Applied Research and Development 100%
Science and Technology Fields ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering) 100%
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Project Contact
No email address given
National Grid Electricity Transmission
Award Type Network Innovation Allowance
Funding Source Ofgem
Start Date 01 June 2018
End Date 31 July 2021
Duration ENA months
Total Grant Value £1,061,000
Industrial Sectors Power
Region London
Programme Network Innovation Allowance
Investigators Principal Investigator Project Contact , National Grid Electricity Transmission (100.000%)
  Industrial Collaborator Project Contact , National Grid plc (0.000%)
Web Site https://smarter.energynetworks.org/projects/NIA_NGTO010
Objectives Three parallel streams of work will be undertaken. The first is focused on developing understanding of the chemical degradation processes of silicone oils in present use. This will be informed by the second, which will involve the development of numerical models of the CSE to investigate the electrical, thermal and mechanical environment that the insulating liquid is subjected to. The third stream will review possible alternative liquids, with a focus on ensuring that their electrical performance and degradation behavior is sufficient for the application. These three streams will run together through the project. The scope of works for the project is as follows:To understand the reasons for the observed behavior of silicone oil, with a focus on the influence of chemical degradation, potential chemical contaminants and compatibility with CSE materials.Determine if other insulating liquids could be used as a replacement for silicone oil in CSE operating at 132kV and above.Confirm whether existing silicone oil CSE can be retrofitted with different liquids, and if so what control measures might be needed to ensure long term performance.Through the use of modelling techniques, determine worst case electrical and thermal conditions that would be experienced by the insulating liquid used in existing CSE designs.Identify tests that can be specified such that the lifetime performance of new liquids could be determined in a laboratory environment.Determine an appropriate field sampling strategy for the testing of CSE oils, including tests to verify that liquids are of sufficient standard prior to use.Inform the development of new specifications for CSE with novel insulating liquids.Working with the ENA, combine present knowledge regarding silicone oil performance into a new silicone oil standard for cable sealing ends. The overall aim of the project is to identify, characterize and verify the long term performance of new insulating liquids which could be used in Cable Sealing Ends.
Abstract Existing polymeric cable sealing ends (CSE) typically contain silicone oil as an insulating liquid between the cable core and the outside of the CSE. In the past year, a number of performance issues have been identified with silicone oil filled CSE. Although these devices are intended to be maintenance free, there is evidence that the insulating liquid is degrading. In some cases, this has led to the electrical degradation of CSEs. A deeper understanding of the chemical degradation of the silicone oil is needed in order to understand the possible reasons for this behaviour. It is also desirable to determine if different insulating liquids (for example, synthetic or natural esters, which have been used in transformers) could be deployed in CSE. The possibility of retrofitting existing CSE would need to be explored, along with any design changes which might be necessitated by the new insulation. Understanding of the long-term ageing of these liquids will be of paramount importance.
Publications (none)
Final Report (none)
Added to Database 09/11/22