Network DC Circuit Breakers

Offshore wind will play a leading role in the transition to net zero, with as much as 100 GW required to deliver 2050 net zero targets.  This will require the development of HVDC networks, not just point-to-point links, to connect and transport offshore wind from source, increasingly further offshore, to areas of demand. To support the development of HVDC networks there is a need to explore and demonstrate the capability of DC Circuit Breakers (DCCBs). Circuit breakers, which already exist on the onshore AC network, minimise the impact of faults, disconnecting the faulted parts only and allowing power to keep flowing elsewhere on the network.

The Network DC project aims to advance the readiness of the technology for implementation on the GB system, to enable the development of offshore DC networks which cannot exist without DCCBs. This is dependent on:

  • developing a supply chain of multiple vendors able to supply DCCBs
  • ensuring that existing designs are practical or can be adapted to address GB network conditions
  • determining the cost of the equipment
  • validating the ability of equipment to isolate faulted sections in response to the majority of credible faults without relying on conventional, slower back-up protection
  • there being no significant integration issues with current design conventions which wind developers, Transmission Owners, Offshore Transmission Operators (OFTOs) and interconnectors are familiar with
  • there being no significant regulatory or commercial barriers to the development of onshore HVDC hubs

This project aims to address these dependencies to allow DCCBs to be selected in future network designs.

At the HVDC Centre we are leading the work package on modelling and simulation of DCCBs, working closely with partners at Edinburgh University and SuperGrid Institute, to derive technical specifications and future testing requirements. This will build on work done previously at the Centre on the European PROMOTioN project. We are also contributing to project activities on cost-benefit analysis, commercial and regulatory barriers, and drafting of tender documents to support future procurement of DCCBs.

A video introducing the project is available here:

Ofgem SIF Discovery project: Network-DC – YouTube

For further please refer to the Energy Networks Association’s (ENA) Smarter Networks Portal as follows:

Network-DC Circuit Breakers (Discovery Phase)| ENA Innovation Portal (

Network-DC Circuit Breakers (Alpha Phase)| ENA Innovation Portal (

The recording of the webinar for this project is available here:

Network DC webinar