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Projects: Projects for Investigator
Reference Number NIA_SHET_0036
Title Condition Assessment of SF6 Alternatives (CASA)
Status Started
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
SSEN Scottish Hydro Electric Transmission
Award Type Network Innovation Allowance
Funding Source Ofgem
Start Date 01 May 2022
End Date 31 December 2025
Duration ENA months
Total Grant Value £700,000
Industrial Sectors Power
Region Scotland
Programme Network Innovation Allowance
Investigators Principal Investigator Project Contact , SSEN Scottish Hydro Electric Transmission (100.000%)
  Industrial Collaborator Project Contact , Scottish and Southern Energy plc (0.000%)
Web Site https://smarter.energynetworks.org/projects/NIA_SHET_0036
Objectives The project will propose new steps in understanding the underlying physics of partial discharge in the alternative gases, for example, direct PD measurement, or simultaneous measurement using radio frequency and conventional techniques may yield vital information on the shape of the underlying current pulse which is otherwise unavailable using either technique separately.Using a new technique developed by the University of Cardiff which allows true simultaneous measurement, where all PD data is captured from the source irrespective of the relative sensitivities of each measurement system, better characterisation of the PD properties of alternative gas mixtures will be possible. To give effective diagnostic information concerning the severity of PD activity and the integrity of an insulation system, the project will establish the defects in alternative gas mixtures:(1) Correlations between RF PD data, conventional PD data, and data from other systems such as optical and acoustic.(2) Establish characteristic PD patterns for the appropriate alternative gases that are most sensitive to the type, severity and location of the defect.(3) Establish characteristic PD features which may be extracted in the absence of a phase-reference.The principal objectives will be as follows:• Commission an experimental test setup that will allow the study of PD events for a variety of discharge sources and geometries such as sharp protrusions, voids, free metallic particles, surface discharges and floating components in a full-scale system.• Characterise phase-resolved partial discharge patterns for various alternative gas mixtures across a range of defect topologies, identifying features that reveal defect type, severity and location. Develop and test a new system for true simultaneous measurement of RF and conventional PD signals, analysing phase-resolved data, individual pulse characteristics, and directly measured current pulses.• Validate findings and enhance understanding of PD physics in alternative gases through on-site measurements and PD monitoring data from online UHF sensors and gas samples. Comparison with lab data will establish correlation and variations that are key to characterising the defect.• Explore recommendations for extension to the IEC60270 and IEC62478 measurement standards. The outcomes will widen applicability of the standards and the quality of diagnostic information available to power network equipment operators in the future.Any developments which can facilitate the use of SF6 alternatives produces a net environmental benefit to consumers through the reduction of SF6 use in GIS. By understanding the characterisation of the Partial Discharge properties of alternative gas mixtures giving greater confidence to network operators when assessing the integrity of online GIS.The strategies proposed will provide key insights into the type and severity of defect(s) in these systems resulting in a greater chance of detecting defects earlier and therefore intervening in a planned way when the implications are less severe. Knowledge acquired over the course of the investigation will contribute to advancing industry and international measurement standards, while providing vital diagnostic data to network operators.The reduction in use of SF6 assists in meeting our T2 business plan objective of reducing our greenhouse gas emissions by 1/3, as well as being consistent with government net-zero emissions targets.
Abstract As part of Network for Net Zero strategy, SSEN transmission are migrating to alternative gases which have lower carbon footprint than sulphur hexafluoride (SF6) for Gas Insulated Systems (GIS) within the transmission network. However, there is industry wide knowledge gap in the key features related to condition monitoring of the alternative gases which may result in an inability to correctly manage future GIS that use the alternative gases. This research will provide full understanding of the condition monitoring requirements of the alternative gases to allow engineers to identify an incipient failure and carry out repairs, mitigating potential lost revenue or regulatory fines.

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Added to Database 14/10/22