Browsing by Keyword "info:eu-repo/grantAgreement/EC/FP7/262552/EU/Marine Renewables Infrastructure Network for Emerging Energy Technologies/MARINET"
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Item Analysis of electrical drive speed control limitations of a power take-off system for wave energy converters(2017-12) Gaspar, José F.; Kamarlouei, Mojtaba; Sinha, Ashank; Xu, Haitong; Calvário, Miguel; Faÿ, François-Xavier; Robles, Eider; Guedes Soares, C.; Tecnalia Research & Innovation; RENOVABLES EFICIENCIA ENERGETICA Y CIRCULARIDAD; RENOVABLES OFFSHOREThe active control of wave energy converters with oil-hydraulic power take-off systems presents important demands on the electrical drives attached to their pumps, in particular on the required drive accelerations and rotational speeds. This work analyzes these demands on the drives and designs reliable control approaches for such drives by simulating a wave-to-wire model in a hardware in-the-loop simulation test rig. The model is based on a point absorber wave energy converter, being the wave, hydrodynamic and oil-hydraulic part simulated in a computer that sends and receives signals from the real embedded components, such as the drive generator, controller and back-to-back converter. Three different control strategies are developed and tested in this test rig and the results revealed that despite the drive limitations to acceleration levels, well above 1 × 104 rpm/s, these do not significantly affect the power take-off efficiency, because the required acceleration peaks rarely achieve these values. Moreover this drive is much more economical than an oil-hydraulic and equivalent one that is able to operate at those peaks of acceleration.Item Control strategies for combining local energy storage with wells turbine oscillating water column devices(2015-11-01) Ceballos, Salvador; Rea, J.A.; Robles, Eider; Lopez, Iraide; Pou, Josep; O´Sullivan, D.; O'Sullivan, Dara; POWER ELECTRONICS AND SYSTEM EQUIPMENT; RENOVABLES OFFSHOREThis paper proposes three generator control strategies for Wells turbine-based floating oscillating wáter column (OWC) devices comprising electrical or mechanical energy storage systems. The first control strategy is indicated for low inertia turbine OWC devices that include ultracapacitors. This control law optimizes the power take-off efficiency by means of an instantaneous speed controller that allows variation of the turbine rotational speed in a wave-by-wave basis. In addition, the profile of the electrical power injected into the grid is smoothed, so that a high penetration of wave energy does not threaten the grid stability. The second and third control laws are developed for OWC systems comprising a flywheel. Quasi-constant and variable speed controllers are proposed. These control laws do not maximize the system efficiency but allow the use of simpler, smaller and cheaper power electronics. Additionally the power quality is also optimized. The development of the proposed control algorithms is accomplished by means of simulations and verified with an experimental test rig.Item An Iterative Refining Approach to Design the Control of Wave Energy Converters with Numerical Modeling and Scaled HIL Testing(2020-05) Delmonte, Nicola; Robles, Eider; Cova, Paolo; Giuliani, Francesco; Faÿ, François Xavier; Lopez, Joseba; Ruol, Piero; Martinelli, Luca; Tecnalia Research & Innovation; RENOVABLES OFFSHORE; RENOVABLES EFICIENCIA ENERGETICA Y CIRCULARIDADThe aim of this work is to show that a significant increase of the e_ciency of aWave Energy Converter (WEC) can be achieved already at an early design stage, through the choice of a turbine and control regulation, by means of an accurate Wave-to-Wire (W2W) modeling that couples the hydrodynamic response calibrated in a wave flume to a Hardware-In-the-Loop (HIL) test bench with sizes and rates not matching those of the system under development. Information on this procedure is relevant to save time, because the acquisition, the installation, and the setup of a test rig are not quick and easy. Moreover, power electronics and electric machines to emulate turbines and electric generators matching the real systems are not low-cost equipment. The use of HIL is important in the development of WECs also because it allows the carrying out of tests in a controlled environment, and this is again time- and money-saving if compared to tests done on a real system installed at the sea. Furthermore, W2W modeling can be applied to several Power Take-O_ (PTO) configurations to experiment di_erent control strategies. The method here proposed, concerning a specific HIL for testing power electronics and control laws for a specific WECs, may have a more general validity.