Robust RST control for «Basse-Isère» run-of-river cascaded hydro-electric plants

The design of run-of-river hydro-plant automation remains a challenge in combined terms of performance and security. This paper presents an innovative methodology, based on one hand on identification through available measurements, and on the other hand on a control structure including a local water level control added to a feed-forward action. The water level controller, developed from the continuous-time robust pole placement structure of Ph.de Larminat, is examined here in a complete discrete-time framework, and requires only some direct manipulations of the assigned poles. This strategy leads to a very simple and efficient design, with easy to tune RST polynomial controllers, and is able to deal with the trade-offs between robustness, performance and noise sensitivity. Results of experimental application on the "Basse-Isère" cascade are finally presented.