National Grid Sellindge HVDC Convertor Stations

National Grid Sellindge HVDC Convertor Stations

Capula to support life extension of the control and monitoring systems at National Grid’s Sellindge HVDC Converter Station.

Capula has been awarded the design, manufacture, test, install and commission of the Supervisory Control and Data Acquisition (SCADA) System for National Grid’s Ventures Sellindge High Voltage Direct Current (HVDC) converter substation.

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The Sellindge converter station was deployed in an operationally critical part of the UK’s transmission network to increase the capacity and ensure the safe and reliable supply of electricity. It plays a vital role, increasing the UK’s energy security, reliability and capacity by connecting with the French electricity transmission network to bring a number of benefits, including lower cost electricity, increased access to low-carbon energy and improved security of supply.

Sellindge was commissioned in 1986 and has many distributed control and monitoring systems. This latest project aims to support the extension of the operational life of the converter station through a refurbishment programme, with a focus on ensuring interoperability of legacy and the latest control systems.



Capula will be involved in an important part of the refurbishment of the converter station control room, with the replacement of the SCADA system. Consisting of new equipment, upgrading of obsolete, and utilising existing control systems, Capula will integrate these technologies into one control room SCADA and new electronic mimic screen.

Supportable for the next 10 years, the system is operationally future-proofed to ensure the integration of IFA1 with IFA2, with clear upgrade pathways and backwards compatibility to optimise system longevity.

Commenting on the project Chris Smith, Transmission & Distribution Principal Software Engineer, Capula said:

“Capula has been supplying substation control systems for over 25 years and has supported National Grid Electricity Transmission since the early 1990s. I am excited to be working on such a technically challenging project and delighted to now be offering National Grid Ventures our engineering services – maximising availability and uptime while controlling total lifetime cost”.