Efficient and Effective

High Voltage Overhead Line Assessment

Project Data

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The “HV OHL assessment” project aims to determine the typical deterioration rates of HV OHL conductors through testing a representative sample. The key objectives of these tests would be to determine the typical condition of conductors within specified age ranges.

What is the project about?

UK Power Networks has over 24,000 km (comprising of over 280,000 spans) of HV overhead line conductors on its distribution network but holds limited information regarding their age and condition. Conductors are visually assessed from the ground, during routine full patrols, every twelve years. However, there is engineering consensus that visual assessments alone are not sufficient to determine the condition of overhead line conductors, since they only correctly assess the condition of conductors when deterioration of the conductor is at an advance stage and evidence of the deterioration is evident through stranding or bird-caging (deformation of strands) of the conductor. As a result, the existing replacement strategy on HV OHL conductors is reactive (apart from load related reinforcement), and HV OHL conductors are replaced when they have failed (post-fault repair).

How we’re doing it

“The objectives of this project include:

  1. Developing and performing a set of tests which test the mechanical, structural and electrical parameters of the OHL samples.
  2. Calculation of the deterioration rate and expected end of life for HV overhead line conductors.
  3. Development of an algorithm that determines the condition and expected end of life for HV overhead conductors based on a set of attributes (e.g. age, location, size).”

What makes it innovative

The project is innovative because it is using existing technology (i.e. known tests on conductors) to develop a novel process to improve the knowledge of the wider electricity distribution industry regarding HV conductor deterioration rates and condition assessment. The key innovative aspect of this project is the development of an algorithm which estimates the condition and expected end-of-life of HV overhead line conductors, based on a set of attributes (e.g. age, location, and size). A review of literature and past projects on similar initiatives did not reveal any projects with similar scope on HV OHL conductors.

What we’re learning

This project has a high potential to deliver new learning with regards to:

  1. The impact of different attributes like age/location/type on the deterioration rate of HV overhead line conductors.
  2. Verify/challenge existing widely held views or assumptions on HV overhead line conductor deterioration e.g. copper “lasts for ever”.
  3. The development of test-based rules to estimate the condition and expected end-of-life of HV overhead line conductors.
  4. Understanding the condition of the existing HV overhead line network through testing a representative sample.

The learning from the project will be shared via the ENA smarter networks portal and other industry portals via reports.

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