Model predictive control of compact combined cycles in offshore power plants integrating a wind farm

Abstract

Model predictive control of compact combined cycles in offshore power plants integrating a wind farm

Combined cycle gas turbine plants (CCGTs) fulfill an important role in emission reduction of offshore power systems as the bottoming cycle (BC) produces additional power from exhaust heat of the gas turbines (GTs). With increasing integration of wind turbines, CCGTs offshore must be flexible and provide variation management to the offshore energy system across multiple time scales. This work proposes a model predictive controller (MPC) sending setpoints to the CCGT to satisfy demand in the offshore power system under fluctuating wind power. A high-speed surrogate model suitable for optimizing in an MPC is identified. A linear MPC using a quadratic cost function with process constraints is formulated. The model-based control structure is then validated in simulation for satisfying a constant power demand under disturbances introduced by fluctuating wind power.