Team Work Delivers a New Control System Upgrade at Drax Power Station

With recent events in the world gas market and with many of the UK nuclear stations coming to the end of their design life, the market is becoming increasingly concerned for the security of supply in the UK. This has led to a marked upturn in electricity wholesale prices, allowing generators to commit to considerable investment in their generating portfolio. Selecting a new control system for a 660MW generating unit in Europe´s largest coal fired power station is not a decision taken lightly. Drax Power Limited have recently had to make this decision in order to help to ensure the security of their generation going forwards, in a continually evolving arena. The chosen system had to have a design life of twenty years and had to be flexible with sufficient expansion capacity to meet current and future environmental demands. The first system to be installed covers one of the three generating units with an I/O count of over 8000 points distributed across 17 dual redundant PLC nodes, communicating on a high speed Ethernet HIPER ring network, handling the real time continuous controls, plant sequencing, interlocking and alarm tagging. The system had to be installed and commissioned within a ten-week outage and it was essential that the unit return to service date was met. The perceived risk of not meeting this requirement was one of the key factors in the choice of the new system and was based on the chosen technology, the commitment and support from the vendor and the capability, commitment and support from the systems integrator. The success of this decision was only achieved by partnership and co-operation between all parties involved in the project.