Case Study: Ripon Cogeneration, which helps supply energy to homes and businesses throughout most of northern and central California, achieved unprecedented plant performance – including a 30 percent reduction in start-up time – by replacing its obsolete distributed control system (DCS) with the PlantPAx process automation system from Rockwell Automation.
With the addition of the new system, Ripon has reduced the number of nuisance trips nearly 90 percent. Multiple fail-safes were hard-coded into the previous DCS, so even small deviations in process variables would trip the entire system offline and force the 50-megawatt-capacity plant to shut down. Operators and technicians at the 25-year-old, gas-fired plant could only react to the safety trips, which occurred as often as three times each day.
“Besides significantly reducing costly shutdowns, the PlantPAx system has helped us comply better with state emissions and other regulations,” said Brett Weber, operations and maintenance manager, Ripon Cogeneration. “That’s because the controls are automated, and operators can easily monitor variables through the PlantPAx dashboards in real time.”
Rockwell Automation power generation engineers collaborated closely with Ripon to align the PlantPAx capabilities with the plant’s specific requirements. The system includes an information-enabled, scalable, multidiscipline control platform that combines process and safety control with communication and state-of-the-art I/O. The system is equipped with 750 I/O points and is able to collect up to 1,000 points of process data. The plant’s old proprietary network was replaced with EtherNet/IP, allowing easy installation of the new system and smooth integration with the existing plant subsystems.
To eliminate the plant’s former error-prone, manual, data-collection process, the PlantPAx system includes data historian software, as well as a visualization, analysis and reporting portal that provides instant insight into production. The PlantPAx system leverages all historical data from the process system and automates daily production reports, allowing plant operators to focus more closely on system operations than on manual reporting.
“The PlantPAx system provides all the core capabilities expected in a world-class DCS – plus the multiple benefits of a single, cohesive, open communication protocol,” said Steve Pulsifer, director, Process Market Development, Rockwell Automation. “By implementing a modern DCS, Ripon Cogeneration now has the flexibility to respond to external pressures, such as regulatory compliance, while increasing efficiencies and productivity across its operation.”