Closed-Loop Identification of Hammerstein Systems with Application to Gas Turbines

Abstract

Many practical applications, such as the fuel control of a gas turbine engine, can be modeled by a feedback connection of a linear controller in series with a Hammerstein system, where the nonlinearity provides a representation of the control element or actuator. An iterative gradient-based method is proposed to simultaneously identify the nonlinear fuel valve characteristic and a low-order linear plant model in gas turbine applications that leverages a priori knowledge of both the nonlinearity and engine dynamics. The identification is a nonlinear prediction error minimization method in a closedloop Hammerstein model framework. It is applied to data from a high-fidelity simulation of a 5 megawatt Taurus T M 60 industrial gas turbine.

Identification of Hammerstein-Wiener Systems in Closed-loop

“…In fact, a subspace identification method is developed for MIMO closedloop Hammerstein systems [15]. Also, the instrumental variables (IV) method [16,12] and an iterative prediction error method (PEM) [13] are applied to the closed-loop identification of Hammerstein systems. To the best of our knowledge, however, less attention has been paid to the identification of NLN systems in closed loop, although NLN models have been widely used for model predictive controls [3,7,19], and process controls [27,26].…”

Global Parameter Estimation of Hammerstein Systems with Polynomial Nonlinearity

“…A Hammerstein-type system consists of a static nonlinearity followed by a linear dynamic subsystem. It has been widely studied in modeling nonlinear systems [1]- [7]. Various identification methods have been developed for the Hammestein-type nonlinear systems.…”