Emerson Process Management has replaced aging turbine and balance-of-plant controls with its Ovation™ expert control system at Westport 5 Generating Station in Baltimore, Maryland. The controls upgrade has helped this critical Exelon Generation unit improve starting reliability by 50 percent.
Controls upgrade of complex high-capacity generating unit also results in 80-90 percent improvement in ability to quickly and consistently reach full load
PITTSBURGH (August 21, 2013) — Emerson Process Management has replaced aging turbine and balance-of-plant controls with its Ovation™ expert control system at Westport 5 Generating Station in Baltimore, Maryland. The power plant is owned by Exelon Generation.
This 116-MW, simple-cycle peaking unit has a unique configuration consisting of eight Pratt & Whitney high-capacity aircraft GG4-7 gas generators coupled with four Worthington Model ER-224 double-flow expander turbines. If any pair of turbines is taken offline, the unit still generates power, as the remaining turbines blend operation to maintain load on the generator. In addition to peak load service, the regional transmission organization relies on the unit to provide emergency blackstart capability to the Baltimore area. Blackstart units are able to self-start and synchronize to the grid without an outside AC power source, making them critical to system restoration.
As part of a $30 million project to update the plant, Exelon Generation selected Emerson to replace the outdated turbine and balance-of-plant controls with its Ovation technology. Emerson completed the project within a compressed schedule of roughly six months. This timeframe – half the time a project of this scope would typically take to complete – was necessary in order for the unit to be available by June 1, 2012, to meet peak summer demand.
“Emerson met every critical deliverable of our aggressive project schedule,” said Carl Johnson, Westport, Shift Forman. “Since the Ovation system has been up and running we’ve experienced 100 percent starting reliability, haven’t had a single forced outage, and have been able to consistently reach full load as required by the regional transmission organization.”
As part of this turnkey project Emerson also installed eight gas-fuel modulation valves, 16 gas-fuel stop valves and eight gas-fuel vent valves. Replacing these valve trains was a key component of the upgrade, as performance of the gas valve trains is critical for maintaining frequency and optimal operation of the unit. Emerson engineered and designed unique logic for load sharing eight engines on one combustion turbine generator. Now, when a Pratt & Whitney engine pair is taken offline, Ovation smoothly redirects the transition of operation to the remaining online turbines. The blending of each turbine’s controls quickly stabilizes plant operation to maintain 60 Hz frequency. In addition to improved availability achieved by being able to quickly and consistently reach full load, the Ovation system also contributes to tighter exhaust temperature control, which helps prolong equipment life and contributes to safer operation of the unit.
“This was not a typical control system replacement, by any means. Our ability to turn around this unique project within a tight timeframe demonstrates the depth and breadth of Emerson’s power plant control capabilities,” said Bob Yeager, president of Emerson Process Management’s Power & Water Solutions. “We have worked with Exelon Generation for a number of years, and are gratified by their continued confidence in our technologies and our people.”