Linear and Non-Linear Observers for Hydropower Plants with Surge Tank

The objective of this article is to investigate which of the best known linear and nonlinear observers can be the most suitable for estimating the states in a low-frequency nonlinear hydraulic model of a hydropower plant with a surge tank, by comparing them to on-site measurements. The model is first given, supported by open loop simulations, and approximate-linearization-based classical Luenberger, PI, as well as Kalman observers are then proposed. EKF and High Gain designs are finally presented as possible nonlinear approaches.