Linear and Nonlinear Model Predictive Control of a Wave Energy Converter
Abstract: The topic of this thesis has been to design a regulator that maximizes the energytransfer from kinetic wave energy to electrical energy. The wave energyconverter used, is of the heaving point absorber type, which is developed bythe company CorPower Ocean AB. Two models have been used, a linear modeland a model in which a selection of nonlinear forces have been active. A Linearand Nonlinear Model Predictive Controller have been developed, usingMatlab’s optimizer fmincon. The cost function of these controllers has alsobeen varied in an attempt to take the infinite horizon into account, using aterminal weight. In order to get an idea of the performance, these controllerswere compared with a differently formulated Model Predictive Controller thatused Matlab’s optimizer quadprog. The latter generally performed betterwith respect to extracted energy. It seemed as the choice of optimizer couldhave an impact on the results. When nonlinear drag and net restoring stiffnessforces were introduced to the model, the Nonlinear Model Predictive Controllerincreased the output energy compared to its linear counterpart.
AT THIS PAGE YOU CAN DOWNLOAD THE WHOLE ESSAY. (follow the link to the next page)