Optimal operation of tidal plants based on nonlinear model predictive control strategy

Abstract

Tidal range barrage is a well-recognized approach to extract energy from tides in a large scale. Nevertheless, the complexity of tide oscillation poses a challenge to efficaciously regulate this type of plants. Optimization of the process control may result in enhancement of energy yield with low influences on environment. This paper presents a framework where the whole tidal-electric system is modelled and coupled with a nonlinear model predictive control (NMPC) strategy to determine the optimal state of turbo-generators over a complete spring-neap cycle in a month. The method allows the system model to be nonlinear and dynamic under tight constraints, which would be extremely appropriate for the deployment of this highly predictable but frequently varied energy. A potential bay in Norway is chosen to be a proposal site to verify the benefits of the control strategy, by comparing the energy extraction between a simple barrage without sluices and a conventional one with sluices assembly. Results show the conventional barrage type is superior with respect to energy generation, while keeping the turbine blade diameter as as factor. For excessively large turbines, though, the revenue may be curtailed by costs due to environmental factors, and turbine construction.