Invensys Operations Management provides a best-in-class water supply control system using a Foxboro® I/A Series® distributed control system (DCS). Recent implementations have provided improvements to the operating concept, improved start-up and run-time performance, and significantly reduced unplanned unit trip interruptions.
These advanced control techniques reduce the interaction required by the operator and increase the time for automatic control—including tripping most units during start-up and shutdown—making the overall control system more capable of handling process anomalies and normal operation.
For all cases, when there is no “no valid input”. Control “actions” are blocked Fail-safe actions are enforced Control is transferred to manual where applicable, leaving the plant in a known state. In addition, each process measurement parameter is evaluated according to its specific, appropriate action to be taken when there is “no valid input”. Redundant sensor algorithms have been used in feedwater control to take measurements such as steam, generator level, steam generator feedwater flow, steam generator steam flow, feedwater pressure, and steam pressure.