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Projects: Projects for Investigator
Reference Number NIA_SPEN0021
Title Endbox G38 Level Detection
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
SP Energy Networks
Award Type Network Innovation Allowance
Funding Source Ofgem
Start Date 01 May 2017
End Date 01 May 2018
Duration 12 months
Total Grant Value £80,000
Industrial Sectors Power
Region Scotland
Programme Network Innovation Allowance
 
Investigators Principal Investigator Project Contact , SP Energy Networks (100.000%)
Web Site http://www.smarternetworks.org/project/NIA_SPEN0021
Objectives The main objectives of this project regard the use of an ultrasound device to allow the level of G38 compound in an end box to be determined. This will require the verification of the technique on a wide variety of end boxes resulting in the generation of a policy document which will inform the further use of ultrasound devices in this way, and provide a framework for other licensees to make use of ultrasound equipment to detect G38 levels. The delivery of the above objectives, within budget and within agreed timelines, as is reasonable depending on the knowledge at this stage of the development phase. The project will be managed within SPEN applying due diligence and best practices where appropriate.
Abstract A large number of transformers and switchgear on our networks use G38 compound in their endboxes as an insulator. The endboxes should be either full or almost full of G38 to ensure safe operation and reduce the risk of a flashover occurring. However, the G38 can leak out of the end box down the cables or through gaps in the box. Additionally, air pockets or voids may form in the body of the compound. Both of these issues will reduce the effectiveness of the G38 as an insulator, and can cause a flashover if not addressed. Identifying these issues is difficult, however; while the G38 which leaks can stain the endbox or form puddles, these cant always be identified as G38 leaks, and are often cleaned up with no follow-up action. As such, endboxes with reduced levels of G38 are often unidentified. As a result, there have been a number of instances where a flashover has occurred, causing a large amount of damage to the substation and the substation equipment. Previously, it had been suggested that a hammer or mallet could be used on the end box at various levels, and the resultant sound listened to determine where the G38 level was. Aside from the safety concerns this raises (that is, that hitting an empty or partially empty end box with a hammer could cause internal damage that leads to a flashover), initial tests have shown that the sound difference is minimal and not sufficiently perceptible, due in part to the thickness of the end box metal.A large number of transformers and switchgear on our networks use G38 compound in their endboxes as an insulator. The endboxes should be either full or almost full of G38 to ensure safe operation and reduce the risk of a flashover occurring. However, the G38 can leak out of the end box down the cables or through gaps in the box. Additionally, air pockets or voids may form in the body of the compound. Both of these issues will reduce the effectiveness of the G38 as an insulator, and can cause a flashover if not addressed. Identifying these issues is difficult, however; while the G38 which leaks can stain the endbox or form puddles, these cant always be identified as G38 leaks, and are often cleaned up with no follow-up action. As such, endboxes with reduced levels of G38 are often unidentified. As a result, there have been a number of instances where a flashover has occurred, causing a large amount of damage to the substation and the substation equipment. Previously, it had been suggested that a hammer or mallet could be used on the end box at various levels, and the resultant sound listened to to determine where the G38 level was. Aside from the safety concerns this raises (that is, that hitting an empty or partially empty end box with a hammer could cause internal damage that leads to a flashover), initial tests have shown that the sound difference is minimal and not sufficiently perceptible, due in part to the thickness of the end box metal. We have carried out an initial test of ultrasonic technology which has given us confidence that this technique has the potential to provide a reliable indication of G38 level. The project will develop a framework and methodology for determining whether an end box has a low level of G38 compound. This will be developed through the use of ultrasound equipment, applied in a novel way, and with experimentation to determine the optimum equipment and parameters for that application.Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above
Publications (none)
Final Report (none)
Added to Database 14/08/18