Supplementary control systems ߞA demonstration

Supplementary Control Systems (SCS, fuel switching, load shifting, environmental dispatch or intermittent controls), which control SO
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emissions as a function of meteorological conditions in order to maintain ambient air quality, offer a means for obtaining improved ambient air quality, conservation of clean fuel, a more reliable energy supply and consumer savings. The design and implementation of a complete SCS currently being tested on four coal-fired plants totaling 4758 mw is described. The components of the SCS design include plant control strategies, meteorological forecasting, and air quality modeling and monitoring; emphasis is placed on the maintenance of air quality in a reliable manner. An innovative air quality modeling approach which complements the demonstration and employs state estimation techniques is discussed.