Nonlinear Control by Coordinated Feedback Synthesis with Gas Turbine Applications

Broadly understood, the tasks of a feedback controller are to close loops and to inject signals into those loops. The performance of a feedback control system depends upon both of these tasks, which are interdependent. In this paper, we study conditions under which the tasks may be separated. In a most general setting, we define separation in terms of the assumption that a match between desired and actual loop responses implies zero feedback action. It is then shown that such a feature implies what may be termed feedforward signal coordination; moreover, under slightly stronger assumptions, such signal coordination implies separation. All the ideas are illustrated in terms of a three-input, three-output gas turbine simulation.