Numerical Modeling and Ocean Testing of a Direct-Drive Wave Energy Device Utilizing a Permanent Magnet Linear Generator for Power Take-Off

Abstract

For the past several years an inter-disciplinary research group at Oregon State University (OSU), working in conjunction with Columbia Power Technologies (CPT) has been researching innovative direct-drive wave energy systems. These systems simplify the conversion of wave energy into electricity by eliminating intermediate energy conversion processes. In support of this research OSU and CPT have developed a hybrid numerical/physical modeling approach utilizing a large scale linear test bed (LTB), and a commercial coupled analysis tool. This paper will present an overview of this modeling approach and its application to the design of a 10kW prototype wave energy conversion system that was tested in the open ocean in the fall of 2008. The data gathered during ocean testing was used to calibrate the numerical model of the device and predict the energy capture potential of the system.

Review on wave energy technologies and power equipment for tropical reefs

“…The Oscillator float structure consists of floating body, energy conversion mechanism, generator, protective shell, and other components, as shown in figure 11 [24].The floating body works as the wave receiving body [25]. It collects energy and transfer it to energy conversion mechanism, thereby generated stable hydraulic energy.…”

Modeling Innovative Power Take-Off Based on Double-Acting Hydraulic Cylinders Array for Wave Energy Conversion

“…The fixed displacement hydraulic motor is modeled taking into account constant volumetric, ηv, and hydraulic-mechanic, ηmech, efficiencies, the nominal pressure, pnom, the angular speed, ωMH, and several characteristics of the hydraulic fluid such as the fluid kinematic viscosity, υ, and the fluid density, ρ. Hence, the flow through the hydraulic motor is governed by Equation (9) [50], whereas the generated torque is calculated using Equation (10). The main parameters are described in Table 7, where ∆p represents the pressure drop between the inlet and outlet of the hydraulic motor.…”

“…This is due to the fact that it is responsible for transforming the mechanical energy of the moving body into electrical energy. In addition, the PTO is used to control the WEC in order to optimize the extraction of wave energy [2][3][4][5][6][7][8][9][10].…”

Wave energy: a Pacific perspective

“…To date, CPT has conducted three ocean deployments, testing a first-generation direct-drive point absorber buoy in 2007 [15]. In the autumn of 2008, they deployed a secondgeneration 10 kW device for a total of 5 days that was connected by an electrical umbilical to a power analysis and data acquisition (PADA) system onboard the deployment vessel [16].…”