Transformer Intrascope

Completed

Other Power and Storage Technologies(Electricity transmission and distribution)

Applied Research and Development

ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering)
ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering)

Not Cross-cutting

Project Contact
Scottish Hydro Electric Power Distribution plc (SHEPD)

Network Innovation Allowance

Ofgem

01 April 2013

01 April 2015

24 months

£400,000

Power

Scotland

Network Innovation Allowance

Project Contact, Scottish Hydro Electric Power Distribution plc (SHEPD)

The objectives for the project are: Conduct research into an intrascope probe system based on the concepts of clinical endoscopy and wide-wavelength spectroscopy which can be used for the in-situ analysis of the condition of power transformers’ internal insulation Develop a prototype of the system and perform laboratory tests for functional, mechanical and optical performance Test and demonstrate the prototype on out-of-service transformers and perform necessary enhancements/refinements for testing on operational transformers Test and demonstrate the prototype in the field on an operational transformer on the SHE Transmission network Evaluate the method’s suitability as a condition monitoring tool for transformers and its impact on asset management The three distinct stages of this project are research, development and demonstration. Successful completion of each stage, with sufficient results to inform viability of subsequent stages, will represent success for that stage. Successful demonstration of the system’s suitability or lack of, on an operational transformer will provide enough knowledge about the system and hence indicate overall success of the project.

SHE Transmission, and the other GB Transmission Network Operators (TOs), have a vast amount of ageing infrastructure presently in use on the GB transmission network which means that asset management is becoming an ever-more important factor for the continued operation and maintenance of the network. Many operational transformers are ageing and approaching the latter part of their lives so it is important to be able to monitor their condition and accurately estimate how much longer we can reliably and safely operate them. A useful measure of a transformer’s estimated remaining life in service is through the assessment of its internal winding insulation. The condition and rate of deterioration of the transformer’s internal insulation can be used to assess its remaining life which can then be used for making optimum asset replacement decisions. Presently, the only non-invasive method of assessing insulation condition is through regular analysis of oil samples using Dissolved Gas Analysis (DGA). This method is important but has limitations including its level of accuracy and its reliance upon an up-to-date history of the transformer oil being assessed. SHE Transmission does not have any other tools or systems at present which allow us to directly access and analyse the internal insulation of a transformer without the need to dismantle ("de-tank") the transformer in a factory off site. This is an expensive and time consuming option especially for larger transformers along with the major inconvenience and cost of a lengthy outage time required to inspect the transformer. A valuable tool would be a probe that we could use in-situ, to directly access and assess the internal winding insulation on site without the need for de-tanking and in doing so, minimise potential outage time. The benefit of having a more accurate assessment of transformer health is the possibility of deferring asset replacement and also a better knowledge of transformer ageing and health which could be used to correlate/verify the DGA results. The project, with particular application to power transformers, is based on the technical development and demonstration of an in-situ electrical insulation analyser. GnoSys Global Ltd (GnoSys) has previously developed a methodology based on wide-wavelength spectroscopy which has been incorporated into a hand-held tool. It is however currently limited in practice to de-tanked transformers which severely restricts its application and suitability for on-site transformer testing. During the project, SHE Transmission will work with GnoSys to conduct further research prior to developing and assembling a new intrascope probe system based on the concept of a clinical endoscope construction whilst employing the wide-wavelength spectroscopy methodology. This system will be designed to be much more suited to the end user practical requirements, permitting the in-situ testing of transformers on-site. Once the system has been assembled in a laboratory environment and gone through initial functional and mechanical testing, it will be trialed on a number of spare, tanked primary and supergrid transformers. During this stage, the technology will be verified through destructive testing of the internal insulation. Refinements will also be made to both the hardware and software based on the learning obtained from this test phase. Following the initial primary transformer trial, further trials of the intrascope systemon spare supergrid transformers are required. This is needed to better assess the intrascope’s suitability for application on one of our operational supergrid transformers and reduce the risk of damage to one of our operational assets by acquiring further operational knowledge and practical experience of using the intrascope system. Overall budget and project duration remain unchanged. Providing the testing phase of the project is successful, investigation of an operational transformer on the network will be planned and investigated using the intrascope system. This will be an important stage in the operational application of the intrascope and transfer to business as usual. A suitable transformer will be selected based on age and performance history; SGT3 (a transformer at Tealing Substation Dundee) has been provisionally identified. The project therefore involves the research, development and operational demonstration on the network of the intrascope system.Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above

17/12/18