Dynamics of a Linear Generator for Wave Energy Conversion

2004 ◽  
Author(s):  
Mikael Eriksson ◽  
Karin Thorburn ◽  
Hans Bernhoff ◽  
Mats Leijon
Keyword(s):  
Output Power ◽  
Wave Climate ◽  
High Rate ◽  
Theoretical Studies ◽  
Wave Energy Conversion ◽  
Piston Motion ◽  
Damping Force ◽  
Dc Voltage ◽  
Linear Generator ◽  
Flux Change

A concept is presented where the piston of a seabed based linear generator is directly driven by a buoy on the water surface. A spring is connected to the other end of the piston. Thereby the buoy absorbs energy in two ways. A large number of poles are used as an “electromagnetic gearbox” which gives a high rate of flux change in the stator despite the slow piston motion. The damping force is a function of the velocity and the electric output power. In the studied concept the power from the generator is rectified with a diode bridge. The results of theoretical studies of output power and its interaction with the dynamics of the equation of motion are presented. It is shown that the DC voltage can be tuned to optimize the power production for each wave climate.

Wave Climate Analysis for a Wave Energy Conversion Application in Brazil

2007 ◽  
Author(s):  
Eliab R. Beserra ◽  
Andre´ L. T. Mendes ◽  
Segen F. Estefen ◽  
Carlos E. Parente
Keyword(s):  
Energy Conversion ◽  
Wave Energy ◽  
Wind Waves ◽  
Energy Resource ◽  
Wave Climate ◽  
Northern Coast ◽  
Wave Energy Conversion ◽  
Annual Fluctuation ◽  
Significant Wave ◽  
Climate Analysis

A variety of ocean wave energy conversion devices have been proposed worldwide considering different technology and energy extraction methods. In order to support full-scale prototype design and performance assessments of a conversion scheme to be deployed on the northern coast of Brazil, a long-term wave climate analysis is under development. A 5-year pitch-roll buoy data series has been investigated through an adaptive technique to enhance spatial resolution and allow for accurate wave directionality evaluation. Device design most influential variables such as extreme significant wave height, peak period and directionality were considered. Temporal variability in wave energy levels was particularly investigated for energy resource assessment. The major findings of this work include the narrow directional amplitude of the incident wave and higher significant wave heights of locally generated waves. The estimated energy resource levels agreed well with literature, also showing little annual fluctuation. The wave climate demonstrated to be in full agreement with the large-scale Equatorial Atlantic atmospheric variability, dominated by either local wind waves or by distant storm swells.

Performance of PM Linear Generator Under Various Ferromagnetic Materials for Wave Energy Conversion

2019 ◽  
pp. 113-126
Author(s):  
Izzeldin Idris Abdalla Yagoube ◽  
Taib Ibrahim ◽  
Nursyarizal Mohd Nor ◽  
Perumal Nallagownden
Keyword(s):  
Energy Conversion ◽  
Wave Energy ◽  
Ferromagnetic Materials ◽  
Magnetic Composite ◽  
Wave Energy Conversion ◽  
Element Analysis ◽  
Linear Generator ◽  
Single Coil ◽  
Accurate Performance ◽  
Electromagnetic Characteristics

This chapter examines the influence of the various ferromagnetic materials on the performance of a single-phase tubular permanent-magnet linear generator (TPMLG) for wave energy conversion. Four ferromagnetic materials were considered in this study. They are non-oriented electrical steel, Permalloy (Ni-Fe-Mn), Accucore, and Somaloy 700. The generator equipped with a tubular stator carries a single coil and employs a quasi-Halbach magnetized moving-magnet translator. Therefore, in order to obtain an accurate performance analysis, the nonlinear time-stepping finite-element analysis (FEA) technique has been used. The electromagnetic characteristics, including the magnetic field distributions, flux-linkage, winding inductance, electromagnetic force, and electromotive force (EMF) have been investigated. It is shown that a generator whose stator is fabricated from soft magnetic composite (SMC) materials has potential advantages in terms of ease of manufacture, highest force capability, lower cost, and minimum eddy-current loss.

Sign in / Sign up

Export Citation Format

Share Document