Power Extraction Strategy of a Robust kW Range Marine Tidal Turbine Based on Permanent Magnet Synchronous Generators and Passive Rectifiers

This paper presents a kW range marine tidal current power generation system consisting of a fixed pitch marine current turbine (MCT) with two permanent magnet synchronous generators in the turbine shaft, two diode rectifiers (each rectifier is associated with a permanent magnet synchronous generator) and a DC source voltage. This system is designed for a kW range robust power supply. The specificity of the proposed system is that the two generators have different numbers of turns in their windings and the two rectifiers are in parallel in the same DC source. It has been demonstrated that the proposed system is able to harness very efficiently the energy of the turbine in the whole tidal cycle. The proposed system is interesting because it does not need complex control system and it allows minimizing converter losses costs due to electronic devices as controlled IGBT PWM converters usually used in conventional power generation systems. The analytical results have been confirmed numerically using PSIM software for two kW range generators with the same magnetic circuit and different winding number of turns

Modeling and Control of a Marine Current Turbine Driven Doubly-Fed Induction Generator

This paper deals with the modeling and the control of a variable speed DFIG-based marine current turbine with and without tidal current speed sensor. The proposed MPPT control strategy relies on the resource and the marine turbine models that were validated by experimental data. The sensitivity of the proposed control strategy is analyzed regarding the swell effect as it is considered as the most disturbing one for the resource model. Tidal current data from the Raz de Sein (Brittany, France) are used to run simulations of a 7.5-kW prototype over various flow regimes. Simulation results are presented and fully analyzedThis work has been funded by Brest Métropole Océan

Ocean Energy in Belgium - 2019

B

Marine Tidal Current Electric Power Generation Technology: State of the Art and Current Status

This work is supported by Brest Métropole Océane (BMO) and the European Social Fund (ESF). It is done within the framework of the Marine Renewable Energy Commission of the Brittany Maritime Cluster (Pôle Mer Bretagne).International audienceThe potential of electric power generation from marine tidal currents is enormous. Tidal currents are being recognized as a resource to be exploited for the sustainable generation of electrical power. The high load factors resulting from the fluid properties and the predictable resource characteristics make marine currents particularly attractive for power generation and advantageous when compared to other renewable energies. Moreover, international treaties related to climate control have triggered resurgence in development of renewable ocean energy technology. Therefore, several demonstration projects in tidal power are scheduled to capture the tidal generated coastal currents. Regarding this emerging and promising area of research, this paper reviews marine tidal power fundamental concepts and main projects around the world. It also report issues regarding electrical generator topologies associated to tidal turbines. Moreover, attempts are made to highlight future issues so as to index some emerging technologies mainly according to relevant works that have been carried out on wind turbines and on ship propellers

Potential Hydrodynamic Impacts and Performances of Commercial-Scale Turbine Arrays in the Strait of Larantuka, Indonesia

The Strait of Larantuka, with highly energetic tidal stream currents reaching speeds of up to 3–4 m/s, is a promising site for renewable electricity production from the ocean. This paper presents the results of an assessment regarding the potential hydrodynamic impacts, wake characteristics, and the performances of large scale turbine arrays in the strait. A high-resolution, three-dimensional baroclinic model is developed using the FLOW module of the Delft3D modeling system to simulate tidal currents. The energy of currents is assumed to be extracted by horizontal-axis tidal turbines, which can harness strong bi-directional flow, positioned on sequential rows and alternating downstream arrangements. Enhanced momentum sinks are used to represent the influence of energy extraction by the tidal turbines. Four different array layouts with rated capacities of up to 35 MW are considered. We find that, in the Strait of Larantuka, array layout significantly affects the flow conditions and the power output, mainly due to the geometric blockage effect of the bounded channel. With respect to undisturbed flow conditions in the strait, decreases in current speeds of up to about 0.6 m/s, alongside increases in the order of 80% near-shore are observed. While operating efficiency rates of turbines reaching around 50%–60% resulted during the spring tide in the arrays with smaller rated capacities, the power output of the devices was negligible during the neap tide

Lighting Northern New England with Water: A Comparative Analysis of Wave and Tidal Hydrokinetic Energy Regulation

“Today, no area holds more promise than our investments in American energy. In order to limit our dependence on foreign oil, reduce greenhouse gas emissions, and curtail rising consumer energy costs, the United States has adjusted its energy trajectory to support more actively the “development and integration of new clean and domestic renewable energy resources into the electric grid.” Although some contend the recent emergence of unconventional oil extraction methods, especially shale gas fracking,3 may hedge political support for renewable energy sources, hydrokinetic power provides a highly affordable and renewable, carbon-free energy source-our nation’s largest supply of*324 clean energy. In comparison to renewable wind energies, the fact that water is 832 times denser than air makes the aggregate of “our tides, waves, ocean current, and free-flowing rivers [[[] an untapped, powerful, [and] highly concentrated [] energy resource.” Moreover, hydrokinetic energy may offer the cleanest and swiftest route to energy independence for the United States, particularly for northern New England. This Comment provides a comparative analysis of hydrokinetic energy projects off the northerly coastlines of New England, focusing exclusively on Maine, New Hampshire, and Massachusetts. Part II offers a basic primer on hydrokinetic technology, and how it actually works. Part III navigates through the vortex of federal and state regulations governing ocean energy development in national waters. Part IV considers the measures that Maine, New Hampshire, and Massachusetts have taken to address the dire need for renewable energy through hydrokinetic energy development. Lastly, Part V concludes that the varying degree of success for hydrokinetic energy projects in northern New England is mostly attributable to tempered energy policies, limited state financial resources, understandable distaste for the existing federal regulatory framework, and considerable attention to legitimate environmental, commercial, and recreational interests. In summary, this Comment presents a comprehensive overview of the ways in which hydrokinetic technology is being used to harness the ocean’s power and produce clean, renewable energy for residents throughout “Norumbega” or northern New England

Lighting Northern New England with Water: A Comparative Analysis of Wave and Tidal Hydrokinetic Energy Regulation

“Today, no area holds more promise than our investments in American energy. In order to limit our dependence on foreign oil, reduce greenhouse gas emissions, and curtail rising consumer energy costs, the United States has adjusted its energy trajectory to support more actively the “development and integration of new clean and domestic renewable energy resources into the electric grid.” Although some contend the recent emergence of unconventional oil extraction methods, especially shale gas fracking,3 may hedge political support for renewable energy sources, hydrokinetic power provides a highly affordable and renewable, carbon-free energy source-our nation’s largest supply of*324 clean energy. In comparison to renewable wind energies, the fact that water is 832 times denser than air makes the aggregate of “our tides, waves, ocean current, and free-flowing rivers [[[] an untapped, powerful, [and] highly concentrated [] energy resource.” Moreover, hydrokinetic energy may offer the cleanest and swiftest route to energy independence for the United States, particularly for northern New England. This Comment provides a comparative analysis of hydrokinetic energy projects off the northerly coastlines of New England, focusing exclusively on Maine, New Hampshire, and Massachusetts. Part II offers a basic primer on hydrokinetic technology, and how it actually works. Part III navigates through the vortex of federal and state regulations governing ocean energy development in national waters. Part IV considers the measures that Maine, New Hampshire, and Massachusetts have taken to address the dire need for renewable energy through hydrokinetic energy development. Lastly, Part V concludes that the varying degree of success for hydrokinetic energy projects in northern New England is mostly attributable to tempered energy policies, limited state financial resources, understandable distaste for the existing federal regulatory framework, and considerable attention to legitimate environmental, commercial, and recreational interests. In summary, this Comment presents a comprehensive overview of the ways in which hydrokinetic technology is being used to harness the ocean’s power and produce clean, renewable energy for residents throughout “Norumbega” or northern New England

[Report of] Specialist Committee V.4: ocean, wind and wave energy utilization

The committee's mandate was :Concern for structural design of ocean energy utilization devices, such as offshore wind turbines, support structures and fixed or floating wave and tidal energy converters. Attention shall be given to the interaction between the load and the structural response and shall include due consideration of the stochastic nature of the waves, current and wind