At the 2018 Ovation Users’ Group Conference, a power producer shared their story of how they improved their unit startups through the application of advanced technology.

The US electrical power grid is evolving rapidly as it adds more renewable generation from solar and wind energy sources. This trend is driving the need for large generating fleets to make their current assets flexible and cost competitive. Important challenges to solve include increasing available ramp rates, providing improved grid stability, and increasing turndown and efficiency during startups.

A combined-cycle (CC) power plant can have one or more power blocks (gas turbines and heat recovery steam generators [HRSGs], with steam turbine) that are inherently capable of providing this flexibility by cycling its gas turbines or even the entire power block frequently. This flexibility can be limited by operator and controls variability.

Advanced process control (APC) in the Ovation distributed control system combined with the Emerson project team provided a fully embedded and automated solutions for combined-cycle startups from pre-start line-ups to “ready for dispatch” AGC (Automatic Generation Control). Model Predictive Control (MPC) was used for temperature control and to support the design of the unit ramp rates

This approach minimized operator interactions during startup, providing a consistent approach which reduced fuel usage and reduced emissions during startup. Emerson partnered with this power producer to engineer and deploy these solutions at many of their combined-cycle sites in North America.