IGCC Power Plant Dispatch Using Infinite-Horizon Economic MPC

The Integrated Gasification Combined Cycle (IGCC) possesses a number of 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 directly the objective of maximizing revenue. 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 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.