Enhancing high voltage overhead lines to increase transmission capacity

Manchester researchers are working to optimise components of high voltage overhead lines (OHLs) to increase the transmission capacity of our existing electricity infrastructure. This enables options for increasing power flow through existing lines and aids the production of new line designs, to increase flow while also reducing noise issues.

Hundreds of kilometres of overhead lines (OHLs) run across the UK, connecting homes and businesses to the energy network. As renewable energy starts to be added, capacity must be increased at certain locations. This, combined with growing consumer demand for technologies to support the energy transition – such as electric vehicles – and an ageing network requiring asset management, means our OHL networks must be adapted in order to provide reliable electricity to commercial and residential consumers.

Increasing the capacity of electricity networks

The University of Manchester’s High Voltage Laboratory is leading innovative research that aims to support an increase in the capacity and reliability of the UK energy supply network. A team of energy experts are collaborating on three key areas:

  • Polymeric insulators and novel tower designs.
  • Conductor electromechanical performance.
  • Environmental impact including acoustic performance.

In a collaboration spanning 15 years, a team of Manchester researchers – including Professors Simon Rowland and Ian Cotton, Drs Iain Dupere, Konstantinos Kopsidas, Vidyadhar Peesapati, Roger Shuttleworth, Jeff Robertson and Antonios Tzimas – used their collective expertise, the capabilities of the Lab, and collaborations with companies including National Grid, SSE and UK Power Networks, to devise holistic solutions for application on the live transmission network.

Driving industry innovation

The research spanned a number of areas. These included:

  • Reviewing the ageing process of polymeric insulators, resulting in seminal work on silicone rubber materials, and frameworks for managing outdoor composite insulators.
  • Developing a new approach to insulating overhead line structures, including high-voltage towers that integrate cross-arm and insulator functions.
  • Developing a performance model of OHL conductors that provided improved design rules.
  • Working with UK Power Networks to increase OHL corridor power efficiencies and better understand the implications of using innovative conductor technologies.
  • Partnering with National Grid to develop a unique experimental facility to directly measure noise from energised conductors.

Environmental benefits from novel designs

Manchester’s work on composite insulator reliability enabled National Grid to integrate wide-bodied silicone insulators onto its lines as a standard product. It also enabled the creation of a new low-impact T-pylon, which is now being constructed to connect the Hinkley Point C nuclear power station to the UK grid. The research also helped reduce adverse audible noise in sensitive locations.

Contributing to professional development

As a result of this partnership, a number of Manchester PhD students have been sponsored by National Grid, and eight have been recruited as highly skilled members of staff. The University has also trained 31 existing National Grid Energy Transmission employees through the Electrical Power Systems Engineering MSc.

Making an impact

National Grid estimate that the knowledge generated through this research has resulted in significant savings through optimised use of our transmission assets and capacity.

In addition, Manchester’s innovative approach has tackled other issues that affected public acceptance of overhead lines. For example, design and testing support has enabled National Grid to develop the world’s first T-pylon construction at Hinkley-Seabank, providing a vital connection point, while offering significantly reduced visual impact.

The research helped to solve long-term noise issues on a UK electricity line, providing immediate relief to the community.

Its lasting impact has enabled National Grid to take a leading role in the ongoing transition, driving a low carbon future that ensures reliability and value for the consumer.