Jan 2017
Electricity Transmission
EPRI Research Collaboration on Overhead Lines (P35) 2017
NIA_NGET0209
Complete
Jan 2017
Jun 2018
National Grid Electricity Transmission
David Clutterbuck
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Network Innovation Allowance
None
Overhead Lines and Electricity Transmission Networks
£7,450,000.00

EPRI research projects span across multiple years. Because of this approach, not all of the work in P35 will be realised at the end of 2017. Nevertheless, there is scope for the delivery of a number of reports and guidance documents in 2017. The full scope of research within each project work-stream for 2017 is listed below.

P35.001 - Inspection, assessment, and asset management of overhead transmission lines

Utilities need to understand the condition of their overhead transmission lines to effectively manage and maintain them at their designed level of performance and safety. Inspection and assessment research is needed to understand the current condition of transmission assets, extend the life of those assets while keeping the ageing infrastructure performance at levels that meet the reliability expectations of the public. d the present condition of their conductors, shield wires and hardware, where these severely aged components are located, what caused the degradation, how future designs may avoid premature ageing and how to forecast the replacement schedule. 

P35.011 - Polymer and composite overhead transmission insulators

Polymer insulators offer advantages such as contamination performance, light weight, and vandal resistance. In order to achieve the expected design life, utilities need to understand their design and material characteristics to properly select, procure and apply polymer insulator components. 

P35.013 - Overhead line ratings and increased power flow

The demand for electric power over transmission circuits is increasing at a faster rate than transmission assets were originally built for. This trend is pushing the capacity of many existing transmission circuits to their design limits. 

P35.015 - Qualification, selection and maintenance of advanced conductors

Recently developed high-temperature conductors (also known as advanced conductors, high-temperature low-sag conductors, or simply HTLS conductors) offer the advantages of higher current capacity, lower conductor sag, and lower line losses than conventional ACSR (aluminium conductor steel-reinforced) conductors. Knowledge on the long-term performance of HTLS conductors is limited, particularly for newly developed products. 

The objectives for 2017 include the continuation of National Grid’s membership with EPRI P35 and the delivery of a selection of reports and guidance documents associated with the five work-streams by undertaking the following:

P35.001 - Inspection, assessment and asset management of overhead transmission lines

  • continued development of tools and methods to help improve reliability
  • increase the effectiveness of the inspection and assessment process
  • increase the safety for the public and transmission owner personnel by helping to detect components with a high risk of failure before the actual event through new inspection methods and hands-on tech transfer

P35.002 - Conductor, shield wire and hardware corrosion management

  • understanding the potential of using near infra-red (NIR) spectroscopy to determine degradation rates and remaining conductor life
  • continued development of NIR spectroscopy technology application for condition assessment of degraded hardware or component surfaces
  • continued assessment of methods to derive new aging algorithms for atmospheric hardware

P35.011 - Polymer and composite overhead transmission insulators

  • multi-stress ageing tests to understand various modes of degradation and performance of polymer components
  • continued development of the failure database to help identify trends and attributes to failures
  • developing short duration, small scale tests that are representative of in-service stresses. The tests may be included in utility specifications
  • inspecting service-aged insulators to aid in understanding how insulators age and the factors of aging which in turn helps improve applications and improve reliability and performance.
  • development of E-field modelling software to help model the electric field on new or existing insulator designs

P35.013 - Overhead line ratings and increased power flow

  • continued development of software tools
  • continued development of rating methodologies
  • continued development of EPRI guidebooks, reports, and training materials for implementing increased power flow strategies, and for training their engineers on increased power flow technologies

P35.015 - Qualification, selection and maintenance of advanced conductors

  • developing a test protocol to compare different carbon fiber composite core conductors
  • providing information on comparing and selecting suitable HTLS conductors for specific applications
  • developing maintenance procedures and recommend that can be incorporated into utility’s maintenance manuals

Continuing to expand National Grid’s knowledge and to deliver value to our stakeholders, participation in P35 during 2017 means the provision of a range of specific outputs across the five work-streams.

P35.001 - Inspection, assessment, and asset management of overhead transmission lines

Continued development of a mix of tools, technology transfer methods and events, and information that will help members improve their line inspection and assessment as well as asset management approaches, with the production and issue of update reports when they become available.

P35.002 - Conductor, shield wire and hardware corrosion management

Continued development of effective inspection techniques, and forecasting the need for maintenance or repair operations. These will help address issues related to conductor, shield wire and hardware corrosion, with the production and issue of update reports when they become available.

P35.011 - Polymer and composite overhead transmission insulators

Continued development of a mix of software tools and information that will help address issues related to the selection, application and inspection of polymer insulators, with the production and issue of update reports when they become available.

P35.013 - Overhead line ratings and increased power flow

Continued development of tools and information that will help address issues to optimize and increase the ratings of their transmission circuits, with the production and issue of update reports when they become available.

P35.015 - Qualification, selection and maintenance of advanced conductors

Continued development of tools and information that will help address issues related to the qualification, selection and maintenance of advanced conductors, with the production and issue of update reports when they become available.