Industrial & Engineering Chemistry Research, Vol.52, No.9, 3151-3164, 2013
IGCC Power Plant Dispatch Using Infinite-Horizon Economic Model Predictive Control
The Integrated Gasification Combined Cycle (IGCC) possesses many benefits over traditional power generation plants, ranging from increased efficiency to flex-fuel and carbon capture opportunities. A lesser-known benefit of the IGCC configuration is the ability to load track electricity market demands. The idea being that process modifications to enable dispatch capabilities will allow for a time-shift of power production away from periods of low energy value to periods of high value. The work begins with an illustration of Economic Model Predictive Control (EMPC) as a vehicle to exploit dispatch capabilities by pursuing the objective of maximizing revenue directly. However, implementation of EMPC can result in unexpected and, at times, pathological closed-loop behavior, including inventory creep and bang bang actuation. To address these issues, an infinite-horizon version of EMPC is developed and shown to avoid many of the performance issues observed in the finite-horizon version. The paper concludes with an in-depth discussion of energy value forecasting and how the quality of forecasts can be incorporated into the design of the infinite-horizon EMPC controller.