Model predictive control of combustion instabilities using Closed-loop Paradigm with an incorporated Padé approximation of a phase shifter

In this paper, the thermo-acoustic coupling between a laminar pre-mixed flame and an existing Helmholtz mode in a combustion chamber in various operating points (OPs) is studied experimentally. A parametric reduced order model is employed to represent the system in both stable and unstable OPs and the corresponding values of the model parameters in each OP are obtained. The model is then used in a Model Predictive Controller (MPC) for predicting the future behavior of the system. The Padé approximation of the phase shifter is transformed to its equivalent state feedback regulator, which can stabilize the real system, although in a limited range of OPs. Then, by proposing a novel Closed-Loop Paradigm which uses this regulator as an internal stabilizer of a dual-mode MPC, we improved the controller performance in a wider range of OPs.