Mar 2013
Electricity Transmission
33kV Fault Current Limiter
Mar 2013
National Grid Electricity System Operator
National Grid TO Innovation Team
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Innovation Funding Incentive
Gas Transmission Networks
Government targets for reducing carbon emissions mean the UK needs to reduce its dependence on fossil fuels and adopt cleaner energy sources. Generators using renewable energy are sited near their energy sources (on hills for wind, by the sea for tidal and wave power, near landfill sites or digesters for gas, etc). Combined heat from the process of generating electricity, need to be installed in locations where there is a need for heat. These sites are rarely connected to the NG system and in any case connecting to this voltage level would be unfeasible for generators of moderate capacity (typically under 50MW) which are likely to be connected in Sheffield.
Key learning to be delivered by the project is the understanding of the circumstances under which the Superconducting Fault Current Limiter (SCFL) can be used to mitigate fault level issues which are a barrier to Distributed Generation (DG) connection and how the SFCL can then be designed into and operated.

Specifically the following learning outcomes would be expected:

  • Identification of network and physical circumstances where use of the SFCL could be used to mitigate fault level issues and address potential future DG connection issues.

  • Identification of design, construction, commissioning, protection, control and operational issues associated with use of such equipment. If the trial proves successful in mitigating faults this could also reduce the need for transmission reinforcements across GB

  • Assessment of actual carbon benefits/confirmation of initial carbon case

  • Assessment of impact of equipment on policies, codes of practice, section level procedures, financial authorisation processes (including the financial justification) and identification of required revisions

  • Dissemination will be through the production of a how to manual that details the new knowledge outlined above.

Demonstration Objectives:

  • This project trials a specific piece of new equipment that has a direct impact on the operation and management of the distribution system and potentially the transmission system.

  • Phase 1 aims to identify suitable locations for the SFCL installation and undertake a feasibility and systems readiness study to analyse the network, outline the optimum application and specification, and confirm the business and carbon cases. This has been completed.

  • Phase 2 intends to design, build, install and commission a three-phase 33kV SFCL on the CE distribution network. It is proposed, subject to site surveys and agreement with NG and other partner organisations, that the unit is installed at a 275/33kV substation in South Yorkshire to limit the fault current to within the rating of the 33kV switchgear. This is currently managed through an operational management switching procedure which in some circumstances may increase the risk of loss of supplies to customers.