Once this standardized approach was established, we set out to evaluate and implement each unit’s upgrade starting with Unit 3, a conventional gas-fired boiler with Foxboro I/A controls. We replaced the existing control system and converted and modernized the existing logics, graphics and control system interfaces. We also redesigned the electrical system to eliminate hardwired circuits and incorporated the functionality into the new Emerson Ovation control system.
With Unit 3 upgraded to the new platform, our team began work on Unit 5, a 2-on-1 combined-cycle unit with GE Mark VIe gas turbine controls and Fuji Micrex programmable logic controller (PLC) steam turbine controls. Both the gas turbine and steam turbine controls were brought into the Ovation DCS. We also integrated the existing PLC-based duct burners into the Ovation system, as well as the gas turbine water wash skid and excitation controls, eliminating the need for various data links.