Saint-Venant reduced order model for water level control in open channels

Abstract : Water level control in open channels used forhydroelectric production is adressed in this paper. In orderto use classical methods of controller design, a new reducedorder model based on Saint-Venant equations is proposed. Itis derived from irrational transfer functions developed withthe WKB method for any non-uniform subcritical flow regime.The reduced model captures the first two modes. A comparisonof open-loop simulations with the proposed 5th order plusdelay transfer functions and with numerical non linear modelis performed. The inputs of the simulations are given byon-site measurements to show the accuracy of the model inrealistic conditions. Based on the resulting model, a robusttuning of controller is developed. It consists of a two-degree-offreedomproportional integral controller. Time domain scenariiare shown to illustrate the closed-loop performance.