scholarly journals A Comparative Analysis of Self-Rectifying Turbines for the Mutriku Oscillating Water Column Energy Plant

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Erlantz Otaola ◽  
Aitor J. Garrido ◽  
Jon Lekube ◽  
Izaskun Garrido
Keyword(s):  
Comparative Analysis ◽  
Power Plant ◽  
Water Column ◽  
Wave Energy ◽  
Control Strategies ◽  
Oscillating Water Column ◽  
Wells Turbine ◽  
Operation Costs ◽  
Energy Plant ◽  
Energy Harnessing

Oscillating Water Column (OWC) based devices are arising as one of the most promising technologies for wave energy harnessing. However, the most widely used turbine comprising its power take-off (PTO) module, the Wells turbine, presents some drawbacks that require special attention. Notwithstanding different control strategies are being followed to overcome these issues; the use of other self-rectifying turbines could directly achieve this goal at the expense of some extra construction, maintenance, and operation costs. However, these newly developed turbines in turn show diverse behaviours that should be compared for each case. This paper aims to analyse this comparison for the Mutriku wave energy power plant.

Water cycle algorithm–based airflow control for oscillating water column–based wave energy converters

2018 ◽  
Vol 234 (1) ◽  
pp. 118-133 ◽  
Author(s):  
Fares M’zoughi ◽  
Soufiene Bouallègue ◽  
Aitor J Garrido ◽  
Izaskun Garrido ◽  
Mounir Ayadi
Keyword(s):  
Power Plant ◽  
Water Column ◽  
Power Plants ◽  
Water Cycle ◽  
Control Strategies ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Wells Turbine ◽  
Water Cycle Algorithm ◽  
Control Approach

The stalling behavior is a feature of the Wells turbine that limits the generated output power of power plants using this turbine. The NEREIDA wave power plant installed in the harbor of Mutriku in the northern Spanish shoreline constitutes an excellent example of this phenomenon. This article deals with the modeling, simulation and control of an oscillating water column unit within the NEREIDA wave power plant. The stalling behavior is investigated and two control strategies are proposed to avoid it. The first control approach is the airflow control which aims to adjust the airflow in the turbine duct using a proportional–integral–derivative controller tuned with the water cycle algorithm. The second control approach is the rotational speed control adjusting the rotor speed using the rotor-side converter of the back-to-back converter which is wired to the doubly fed induction generator. Results of comparative studies show a power generation improvement even relative to the real measured data.

Analysis of the Wells Turbine Structure of an Oscillating Water Column Wave Energy System

2021 ◽  
pp. 53-62
Author(s):  
Mohamed Ali Jemni ◽  
Hamdi Hentati ◽  
Sawsan Elmbarki ◽  
Mohamed Salah Abid
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Energy System ◽  
Oscillating Water Column ◽  
Wells Turbine

scholarly journals Control strategies for combining local energy storage with wells turbine oscillating water column devices

2015 ◽  
Vol 83 ◽  
pp. 1097-1109 ◽  
Author(s):  
Salvador Ceballos ◽  
Judy Rea ◽  
Eider Robles ◽  
Iraide Lopez ◽  
Josep Pou ◽  
...  
Keyword(s):  
Energy Storage ◽  
Water Column ◽  
Control Strategies ◽  
Local Energy ◽  
Oscillating Water Column ◽  
Wells Turbine

scholarly journals Optimal design of air turbines for oscillating water column wave energy systems: A review

2017 ◽  
Vol 8 (1) ◽  
pp. 37-49 ◽  
Author(s):  
Tapas Kumar Das ◽  
Paresh Halder ◽  
Abdus Samad
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Guide Vane ◽  
Optimization Techniques ◽  
Maximum Efficiency ◽  
Oscillating Water Column ◽  
Peak Efficiency ◽  
Wells Turbine ◽  
Impulse Turbine ◽  
Operating Range

Oscillating water column wave energy harvesting system uses pneumatic power to run a turbine and generate power. Both reaction (mainly Wells turbine) and impulse type turbines are tested in oscillating water column system and the performances are investigated. Reaction turbines are easy to install, and the operating range is narrow and possesses higher peak efficiency. On the contrary, impulse turbines have the wider operating range and lower peak efficiency. Some of the key parameters for Wells turbine are solidity, tip clearance, and the hub-to-tip ratio. Significant performance improvement is possible by redesigning the turbines using optimization techniques. Till date, surrogate modeling and an automated optimization library OPAL are commonly used in optimization of oscillating water column air turbines. In this article, various types of oscillating water column turbines are reviewed, and optimization techniques applied to such turbines are discussed. The Wells turbine with guide vane has the maximum efficiency, whereas the axial-impulse turbine with pitch-controlled guide vane has the widest operating range. Turbines with optimized geometry have better overall performance than other turbines.

A detailed analysis of the unsteady flow within a Wells turbine

2017 ◽  
Vol 231 (3) ◽  
pp. 197-214 ◽  
Author(s):  
Tiziano Ghisu ◽  
Pierpaolo Puddu ◽  
Francesco Cambuli
Keyword(s):  
Detailed Analysis ◽  
Water Column ◽  
Wave Energy ◽  
Oscillating Water Column ◽  
Renewable Energy Resources ◽  
Wells Turbine ◽  
Column System ◽  
Flow Parameters ◽  
Important Interaction ◽  
Acceleration And Deceleration

Sea wave energy is one of the main renewable energy resources. Its exploitation is relatively simple and determines a minimum impact on the environment. The system that is most often used for wave energy harvesting is composed of an oscillating water column device together with a Wells turbine. When designing the Wells turbine, its interaction with the oscillating water column system must be taken into account, if the energy collected is to be maximized. The most important interaction phenomenon is the so called hysteresis effect, i.e. the time delay between the piston-like motion of the air water interface and the torque developed by the turbine. This work presents a detailed analysis of the flow within an oscillating water column system, focusing on the differences in performance and in secondary flow structures between acceleration and deceleration, and between the inflow and outflow phases. This analysis demonstrates how the hysteresis between acceleration and deceleration is caused uniquely by compressibility effects within the oscillating water column system, while differences in the flow parameters and secondary structures near the rotor are negligible, if equivalent flow conditions are compared. The effects of the oscillating water column system configuration on the performance are also highlighted.

Fluidic Components for Oscillating Water Column Based Wave Energy Plants

2011 ◽  
Author(s):  
Prasad V. Dudhgaonkar ◽  
V. Jayashankar ◽  
Purnima Jalihal ◽  
S. Kedarnath ◽  
T. Setoguchi ◽  
...  
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
High Efficiency ◽  
Reverse Flow ◽  
Forward Direction ◽  
Oscillating Water Column ◽  
High Impedance ◽  
Energy Plant ◽  
Wide Range ◽  
Fluidic Diode

A bidirectional (oscillating) air flow is central to energy conversion from wave to wire in an oscillating water column based wave energy plant. Several classes of bidirectional turbines, which operate with such an oscillating flow, have been designed and tested with limited efficiencies. A topology which uses fluidic diodes in conjunction with unidirectional turbines is shown to significantly improve the efficiency. The design and test results from several fluidic diodes for such an application are discussed. It is shown that a combination of a fluidic diode and the unidirectional turbine can achieve a very high impedance to reverse flow while having a high efficiency in the forward direction, over a wide range of flow coefficients.

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