Apr 2014
Electricity Transmission
Impact of HVDC Cable Operation on Telecommunication Lines
Apr 2014
May 2015
National Grid Electricity Transmission
Greg Tzemis
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Network Innovation Allowance
Comms & IT and HVDC
The scope of the project covers the investigation of HVDC Cable Assets and their interactions with Telecommunication Cables. Generally, the available standards applied to induced voltages address electrocution risk, and overlooks the effect on functionality of telecommunication hardware. The published situation is confusing, as CIGRE Technical Brochure 92 indicates that no issues are likely to be experienced if HVDC transmission is via cables rather than overhead lines. VSC Technology further reduces the level of harmonic content, however, as reported on two VSC projects, problems have been experienced. The problems manifested in the telecommunication system by creating a high noise level, making communication impossible.

The objective of this project is determine the exact nature of the problem for both LCC and VSC interconnectors, and the mitigation measures required.

  • Review of specifications related to cable interference issues.

  • Determination of the exact problem as related to LCC and VSC systems in their most common topography.

  • Development of the parameters that need to be collected to completely investigate the problem.

  • Discuss and review mitigation measures and the options available pre, during and post-construction.

  • Development of a mechanism/process suitable for route selection.

  • Discuss mathematical and computer modelling techniques and how these can be utilised & developed.

  • Review measurement techniques and equipment suitable for measuring harmonic currents and induced current.