A nonlinear exponential ARX model-based multivariable generalized predictive control strategy for thermal power plants

This paper presents a modeling and control method for thermal power plants having nonlinear dynamics varying with load. First, a load-dependent exponential ARX (Exp-ARX) model that can effectively describe the plant nonlinear properties and requires only off-line identification is presented. The model is then used to establish a constrained multivariate multistep predictive control (ExpMPC) strategy whose effectiveness is illustrated by a simulation study of a 600 megawatt (MW) thermal power plant. Although the predictive control algorithm may be used without resorting to online parameter estimation, it is much more reliable, and displays much better control performance than the usual generalized predictive control (GPC) algorithm.