scholarly journals Recent Advances in Direct-Drive Power Take-Off (DDPTO) Systems for Wave Energy Converters Based on Switched Reluctance Machines (SRM)

2021 ◽  
pp. 487-532
Author(s):  
Marcos Blanco ◽  
Jorge Torres ◽  
Miguel Santos-Herrán ◽  
Luis García-Tabarés ◽  
Gustavo Navarro ◽  
...  
Keyword(s):  
Wave Energy ◽  
Control Strategies ◽  
Direct Drive ◽  
Drive Power ◽  
Switched Reluctance ◽  
Wave Energy Converters ◽  
Switched Reluctance Machines ◽  
Point Absorbers ◽  
The Waves ◽  
Energy Converters

AbstractThis chapter is focused on Power Take-Off (PTO) systems for wave energy converters (WEC), being one of the most important elements since PTOs are responsible to transform the mechanical power captured from the waves into electricity. It presents Direct-Drive PTO (DDPTO) as one of the most reliable solutions to be adapted to some particular types of WEC, such as point absorbers. A discussion about modularity and adaptability, together with intrinsic characteristics of direct-drive PTOs, is also included. Among the different technologies of electric machines that can be used in direct-drive linear PTOs, switched reluctance machines (SRM) are described in further detail. In particular, the Azimuthal Multi-translator SRM is presented as a suitable solution in order to increase power density and reduce costs. Not only the electric machine, but also the associated power electronics are described in detail. The description includes the different configurations and topologies of power converters and the most appropriate control strategies. Finally, a superconducting linear generator solution is described, presenting it as a reliable alternative for the application of direct-drive PTOs. An example of concept and preliminary design is included in order to highlight the main challenges to be faced during this process.

scholarly journals A Survey of Power Take-off Systems of Ocean Wave Energy Converters

2019 ◽  
Author(s):  
Zhenwei Liu ◽  
Ran Zhang ◽  
Han Xiao ◽  
Xu Wang
Keyword(s):  
Energy Conversion ◽  
Wave Energy ◽  
Clean Energy ◽  
Ocean Wave ◽  
Direct Drive ◽  
Wave Energy Conversion ◽  
Drive Power ◽  
Wave Energy Converters ◽  
Ocean Wave Energy ◽  
Energy Converters

Ocean wave energy conversion as one of the renewable clean energy sources is attracting the research interests of many people. This review introduces different types of power take-off technology of wave energy converters. The main focus is the linear direct drive power take-off devices as they have the advantages for ocean wave energy conversion. The designs and optimizations of power take-off systems of ocean wave energy converters have been studied from reviewing the recently published literature. Also, the simple hydrodynamics of wave energy converters have been reviewed for design optimization of the wave energy converters at specific wave sites. The novel mechanical designs of the power take-off systems have been compared and investigated in order to increase the energy harvesting efficiency.

Emulation and Control Methods for Direct Drive Linear Wave Energy Converters

2013 ◽  
Vol 9 (2) ◽  
pp. 790-798 ◽  
Author(s):  
Zanxiang Nie ◽  
Xi Xiao ◽  
Richard McMahon ◽  
Peter Clifton ◽  
Yunxiang Wu ◽  
...  
Keyword(s):  
Wave Energy ◽  
Linear Wave ◽  
Control Methods ◽  
Direct Drive ◽  
Wave Energy Converters ◽  
And Control ◽  
Energy Converters

scholarly journals Balancing Power Output and Structural Fatigue of Wave Energy Converters by Means of Control Strategies

Energies ◽  
2014 ◽  
Vol 7 (4) ◽  
pp. 2246-2273 ◽  
Author(s):  
Francesco Ferri ◽  
Simon Ambühl ◽  
Boris Fischer ◽  
Jens Kofoed
Keyword(s):  
Wave Energy ◽  
Power Output ◽  
Control Strategies ◽  
Structural Fatigue ◽  
Wave Energy Converters ◽  
Energy Converters

The Economics of Multi-Axis Point Absorber Wave Energy Converters

2013 ◽  
Author(s):  
Daniel S. Richardson ◽  
George A. Aggidis
Keyword(s):  
Wave Energy ◽  
Performance Comparison ◽  
Linear Potential ◽  
Advantages And Disadvantages ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Point Absorbers ◽  
Linear Potential Theory ◽  
Economic Comparison ◽  
Energy Converters

This paper examines the economic advantages and disadvantages of multi-axis point absorber wave energy converters in comparison to conventional heave-only point absorbers. A multi-axis point absorber wave energy converter (MA-PAWEC) is classified as a point absorber device that has a power take off (PTO) system extracting energy from more than one mode of motion (e.g. heave and surge). The majority of existing point absorber devices operate in heave mode alone. Therefore the forces exerted along other axes must be resisted by the mooring system, any reciprocal component of which constitutes a wasted opportunity to extract energy. The economics of PAWECs are governed by the available resource, energy generated by the device, capital cost and operational cost. These factors are examined for MA-PAWECs and compared to a generic heave-PAWEC. For a performance comparison, a simple generic body PAWEC is examined under heave mode operation and multi-axis operation in a representative spectrum. The modelling is based on linear potential theory. The potential advantages of MA-PAWECS are identified as greater energy absorption, fewer installed devices for a given capacity, and greater array control. Disadvantages include higher capex, higher maintenance costs and sensitivity to PTO costs. The performance and costs are assigned an estimated economic scaling factor and are applied to a generic heave-PAWEC for an economic comparison of the two devices. This indicates that a multi-axis approach to point absorbers could offer a 21% lower cost of electricity than the incumbent heave-response devices.

The Fair Evaluation of Wave Energy Converters

2020 ◽  
Author(s):  
Jian Tan ◽  
Henk Polinder ◽  
Peter Wellens ◽  
Sape Miedema
Keyword(s):  
Wave Energy ◽  
Evaluation Method ◽  
Control Strategies ◽  
Optimization Methods ◽  
Size Optimization ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Cost Of Energy ◽  
The Cost ◽  
Energy Converters

Abstract In this paper, a fair evaluation method of WECs (Wave Energy Converters) is established based on frequency domain simulation. In this fair evaluation, size optimization and downsizing of PTO (Power Take-Off) capacity are included to minimize the Cost of Energy for the concerned wave location. Based on this fair evaluation, a techno-economic evaluation of a generic point absorber is conducted for a specific wave location, and two different control strategies of PTO are considered. The results show that this fair evaluation method can contribute to the improvement of techno-economic performance of WECs. Furthermore, a comparison among three different size optimization methods of WECs is performed.

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