Apr 2013
Electricity Transmission
EPRI Research Collaboration on Overhead Circuits.
Apr 2013
Jan 2015
National Grid Electricity System Operator and National Grid Electricity Transmission
Glyn Kirkland
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Network Innovation Allowance
High Voltage Technology, Overhead Lines and Modelling
The Worldwide electricity industry recognises that there are parallel challenges within the field of electricity transmission which are more economically investigated and addressed through collaborative learning and knowledge generation among key industry stakeholders.  The Electric Power Research Institution (EPRI), with its wide international membership, takes a key role in determining and delivering the most impactful R&D projects. This portfolio of work is focused on Overhead and Underground Circuits (OUC) which address key aspects of National Grid’s Innovation Strategy.

Transmission companies face issues such as improving safety and reliability, as well as reducing operations and maintenance (O&M) costs. They are also seeking ways to increase transmission capacity without making large capital investments. Reducing capital expenditures for new and refurbished equipment is another priority.

This EPRI research program is designed to address the research needs of transmission asset owners and operators. The program includes projects focused on specific components (e.g., insulators, compression connectors, conductors, composite poles, and crossarms) as well as projects focused on issues (e.g., lightning and grounding, live working, transmission capacity, and methods to assess the condition of overhead lines).

Conductor, Shield Wire and Hardware Corrosion Management

  • Develop tools and processes for inspecting and assessing overhead conductors, shield wires and hardware
  • Produce management and engineering guides and provide guidance to asset managers.
  • Devise guidelines for inspection, selection and application.
  • Assess fleet management methodology to perform population assessments of phase conductors and shield wires

Compression Connector Management

  • Develop guidelines to assist utilities with the inspection of overhead transmission line compression connectors.
  • Undertake tests to determine the performance of HTLS conductors after routine cleaning.
  • Evaluate the life expectancy of compression connectors operating at 100°C and below.
  • Evaluate compression connectors with known defects.
  • Maintain connectors failure/performance data

Lightning Performance and Grounding of Transmission Lines

  • Evaluation of techniques to improve the lighting performance of lines to include shielding, grounding, insulation and transmission line surge arresters.
  • Establish cost efficiency of different approaches.

Live Working: Research, Techniques and Procedures

  • Review live working methodology to include;  ropes for live work and energized rescue, live work on HV lines and live work with high-temperature conductors
  • Design of structures to facilitate safe, efficient, and economic execution of live work
  • Technology transfer through updating the Tan Book, training videos/DVDs, meetings, and webcasts

Polymer and Composite Overhead Transmission Line Components

  • Evaluation of a range of composite component concerns.
  • Examination of composite components, such as polymer insulators, guy strain insulators, and fiberglass cross arms

Porcelain / Glass Insulator Integrity Assessment

  • Develop a guide to identify insulators and design characteristics
  • Evaluation of porcelain and glass insulators to provide necessary data to make design and procurement decisions
  • improve the Insulator Calculation Engine (ICE) software by adding a library of manufacturer designs
  • track in-service insulator failures

Performance and Maintenance of High-Temperature Conductors

  • Improve comprehensive guide for the selection and application of various types of high-temperature conductors

In the period April 13 to December 14, this research program expects to accomplish these objectives:

  • Develop tools and mitigation techniques to address sub-grade and conductor corrosion

  • Develop guidelines for compression connector management

  • Develop inspection and assessment approaches for composite poles and crossarms

  • Provide state-of-the-art methods for designing transmission line structures

  • Develop live working ropes for new applications

  • Evaluate the performance of lightning detection networks

  • Update the Lightning and Grounding reference book (the Gray Book)

  • Provide composite component accelerated aging results

  • Develop software to aid in selection of corona rings for polymer insulators and electric field calculations on ceramic and glass insulators (ICE)

  • Develop guidelines for the selection and application of various types of high-temperature low sag conductors