Takagi—Sugeno Observers as an Alternative to Nonlinear Observers for Analytical Redundancy. Application to a Steam Generator of a Thermal Power Plant

摘要

Two observer design approaches for analytical redundancy are presented in this work. The first one is based on the use of Takagi—Sugeno observers, whereas the second method is based on nonlinear high-gain observers. The objective is to conduct a comparative study between these two different approaches for a posteriori application of monitoring process and/or fault detection. In order to ensure a fair comparison, both approaches are evaluated on a common case study: the estimation of critical variables in a steam generator for thermal power plants. A well-known simplified nonlinear model for the steam generator proposed by Bell and Astrom is used for the high-gain observer design whereas for the Takagi— Sugeno obsever design, the nonlinear model is transformed into a Takagi—Sugeno form by means of the nonlinear sector approach. The main contribution is to propose the use of Takagi—Sugeno observers for analytical redundancy purposes and to highlight their advantages over the use nonlinear high-gain observers.