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Optimisation technology boosts electricity output

An Emerson Process Management - Power + Water product story

Edited by the Engineeringtalk editorial team May 29, 2008

The SmartProcess URO is part of Emerson's comprehensive suite of optimisation technologies seamlessly embedded within the Ovation expert control system.

At Minnkota's Milton Young station, use of Emerson Process Management's SmartProcess Unit Response Optimisation (URO) technology is translating into dramatic operational gains, including a 70% improvement in ramp rate.

These performance improvements are helping the station generate MW more efficiently as part of the Midwest ISO in which it now participates.

The Young station is owned and operated by Minnkota Power Co-operative, which provides electricity to 11 associated distribution co-operatives in eastern North Dakota and northwestern Minnesota.

Young Unit 1, located near centre, North Dakota, is the primary source of electric energy for approximately 110,000 customers.

This lignite-fired, 250MW unit, which began operation in 1970, is equipped with a Babcock and Wilcox (BandW) cyclone boiler and General Electric steam turbine generator.

For years, Young Unit 1 operated as a base-load unit in which MW production levels remained relatively constant.

This changed when Minnkota recently started participating in the Midwest ISO, an operating environment in which revenue is dependent on a station's ability to quickly and efficiently respond to constantly changing load demand.

This environment was particularly challenging for Young Unit 1, which was now also required to offset MW whenever recently added wind farms are unable to meet demand.

Previously, Unit 1's response to load setpoint changes often resulted in over/undershoot and lagging load response, both of which contributed to lost revenue.

To help resolve this issue, in the fall of 2007 Minnkota implemented Emerson's SmartProcess URO technology to more efficiently meet fluctuating demand.

The SmartProcess URO solution, which uses actual plant operating data to create a model of process response and unit characteristics, has been running continuously ever since.

The results have been dramatic - a 70% improvement in ramp rate, from 2 to 7MW/min, a 2MW reduction in over/undershoot; and a 275mbar average decrease in throttle pressure, contributing to overall machinery health.

As an additional benefit, the SmartProcess solution has also been instrumental in helping Young Unit 1 pass its routine turbine steam inlet valve tests.

"Because the Young Station is now participating in the Midwest ISO, we need to ramp to setpoint more quickly, with reduced variability in MW and pressure", explained Dana Stumpf, Technical Supervisor, Minnkota Power Co-operative, who adds that the SmartProcess URO solution will be installed this year at Young Unit 2.

"Emerson's SmartProcess Unit Response Optimisation technology has significantly improved unit response, which is critical to our capability to operate more profitably".

The SmartProcess URO is part of Emerson's comprehensive suite of optimisation technologies seamlessly embedded within the Ovation expert control system.

Incorporating fuzzy logic, advanced analytics and model predictive control, these technologies offer adaptive improvement solutions which help utilities achieve optimised equipment performance for emissions compliance, temperature control, efficiency and overall continuous operational improvement.

Using nonlinear dynamic feedforward and model prediction, the SmartProcess URO builds upon Ovation's existing unit co-ordinated control capability to further enhance the boiler and turbine response for tighter overall control and more efficient operation.

Use of SmartProcess URO technology translates into additional revenue opportunities for power generators by enabling units to more accurately hit targeted setpoints with minimal MW overshoot, thereby contributing to reduced fuel costs; helping units quickly ramp to targeted setpoints and allowing them to generate revenue as quickly as possible; and enabling units to follow load demand, making it possible for them to compete in the ancillary power services market.

"Emerson understands that the power generation industry's operational and financial climate has never been more demanding", said Bob Yeager, President of the Power and Water Solutions division of Emerson.

"Because of its ability to dynamically optimise plant operations during constantly changing demand, our SmartProcess optimisation technologies can help power producers improve plant economics and achieve a timely return on their optimisation investment".