Browsing by Keyword "info:eu-repo/grantAgreement/EC/FP7/607656/EU/OceaNET/OCEANET"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
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 Electrical Connectors for Underwater Applications(wiley, 2020-01-01) Remouit, Flore; Engström, Jens; Ruiz-Minguela, Pablo; Ruiz‐Minguela, Pablo; RENOVABLES OFFSHORENowadays, numerous companies offer a large choice of underwater connectors and assemblies, and it can be complex to distinguish the different technologies employed for each of them. This chapter provides an overview of the types of connectors that exist for underwater and subsea electrical connections. It presents different types of commercial-off-the-shelf electrical connectors, and lists their performances and defaults, as well as typical failure modes and their known causes. Although each manufacturer has its own designs and technologies, underwater connectors can be grouped into five main categories: rubber-molded, rigid-shell or bulkhead assemblies, fluid-filled underwater mateable, inductive coupling, and assemblies (non-unmateable). The chapter contains the theory on sealing and on connectors’ thermal, electrical, and mechanical properties. It provides information on connection procedures and other details about connecting subsea cables with a focus on the connection of offshore renewable energy farms.Item Latching control of a floating oscillating-water-column wave energy converter(2016-05-01) Henriques, J. C.C.; Gato, L. M.C.; Falcão, A. F.O.; Robles, E.; Faÿ, F. X.; RENOVABLES OFFSHORE; RENOVABLES EFICIENCIA ENERGETICA Y CIRCULARIDADThe OWC spar-buoy is an axisymmetric floating version of an oscillating-water-column (OWC) based device whose power take-off (PTO) system is an air turbine/generator set. Latching has been regarded as one of the most promising techniques to improve the efficiency of wave energy converters. In the case of the OWC spar-buoy, latching control is performed by opening/closing a high-speed stop valve installed in series with the turbine. The present paper has three main objectives. Firstly, to assess the performance improvements that can be achieved with a latching control strategy within a receding horizon framework. Secondly, to establish the practical requirements of this type of control by evaluating the sensitivity of the turbine power output to several receding horizon time intervals. Finally, to test and validate experimentally the proposed algorithms in a small-scale PTO test rig. All the experimental tests were performed considering irregular wave conditions.