Wave Energy Hyperbaric Converter: Small Scale Models, Prototype and Control Strategies

Abstract

A device for electricity generation from ocean waves has been developed for installation on the Brazilian northeast coast. It is based on pumping modules and a two-stage accumulator linked to a hyperbaric chamber in order to provide a prescribed high pressure water flow, which operates a turbine coupled with an electrical generator. In the period between 2001 and 2007, wave tank testing of small-scale models have been carried out. A prototype with two pumping modules is presently installed in the Port of Pecém. This paper describes an overview of the device development since the first tests to the installation of the prototype. Wave climate analysis, design analysis and optimization studies have been developed and are briefly revised in this study. Furthermore, control strategies are proposed to optimize the electrical output considering the proper combination of both pressure and flow rate as a function of the predominant wave climate, when the applied pressure is constant and the generator is a synchronous machine.

A Review of Offshore Renewable Energy in South America: Current Status and Future Perspectives

“…In the totality of 107 scientific publications on ORE in Brazil, a total of 46 include offshore wind subjects, including theoretical, technical and economic potential assessment [22,28,[44][45][46], resource complementarity including hydropower, offshore wind and offshore solar [47,48], offshore wind environmental [34] and social [49] impacts and regulatory aspects [36]. Research about wave energy in Brazil started in 2000, focusing mainly on wave resource potential [50,51], wave-to-wire modeling [52], geometry optimization [53] and control systems and strategies [30,[54][55][56], experimental tests including dry tests [57] and reduced scale models in wave tank [58], economic feasibility [27] and environmental aspects [59] of WECs. Some works, including [31,60] and [23], are examples of studies that addressed tidal, ocean current and OTEC, respectively.…”

Hierarchical control and emulation of a wave energy hyperbaric converter

“…This represents a significant difference in terms of power quality, as with active power control, the inertia of the rotor filters the wave power oscillations, and then, the electrical power exhibits a certain level of filtering when compared to the mechanical power that has not been observed with the DFIG controlled by speed. A full-scale prototype with two floating bodies was installed in the Pecém port, in the state of Ceará in Brazil [25]. Nonetheless, the integration of control strategies applied to the PCU and to the SCU is an important step in the development of the hyperbaric WEC that has not been developed.…”