Turbine Control and Protection System Upgrade

This was a project to replace the obsolete analogue turbine control and protection systems of Koeberg Power Station with a modern, state-of-the-art, digital system. The project included functional improvements to the system and the addition of new field devices to further improve overall reliability of the system. Due to Koeberg’s rapid drive for improved reliability of its operating units, the project was scheduled for implementation in two phases over two consecutive refuelling outages on both units.

These phases were:

Phase 1 – Replacing the obsolete equipment with new, modern equipment, but retaining the previous system functionality and human machine interface in the main control rooms. This allowed the failing equipment to be replaced with more reliable and available equipment whilst minimising the impact on the plant simulator and operator training which were not feasible to complete for a full upgrade prior to implementation.
Phase 2 – Implementing the functional improvements with associated additional field devices and associated interface to the new plant data processing computing system which provided the human machine interface in the control rooms. This phase completed the upgrade by means of improving the functionality, generally from a 1oo2 to a 2oo3 logic for further improvement of the system reliability. This phase also included a mechanical hydraulic upgrade to the servo motors of all the turbine governing and control valves.