The Kinematics of a 3-DOF Mechanism for Wave Energy Converter
As we all know, oceans have great wave power, and many types of wave energy converters (WECs) have been invented so far. Oscillating body systems are a major class of WECs which almost only have one degree of freedom (DOF). This paper presents a 3-DOF mec
- PDF / 494,408 Bytes
- 10 Pages / 439.37 x 666.142 pts Page_size
- 42 Downloads / 215 Views
Abstract As we all know, oceans have great wave power, and many types of wave energy converters (WECs) have been invented so far. Oscillating body systems are a major class of WECs which almost only have one degree of freedom (DOF). This paper presents a 3-DOF mechanism which can extract the wave power from any wave directions. The 3-DOF mechanism mainly consists of a four-bar linkage and a spherical joint, which are used to capture the heave motion and the pitch and roll motions of the oscillating body respectively. The power conversion principle of the WEC is proposed and the kinematics of the mechanism is derived. Keywords WEC
Principle 3-DOF mechanism Kinematics
1 Introduction Ocean is a huge reservoir of renewable energy, such as wave power, tidal power, ocean current power, ocean thermal power, salinity gradient power, etc. Of these types of energy, wave power is deemed as the most notable form [1]. The research enthusiasm of the WEC is raised since the Duck proposed by Salter in 1974 [2]. So far, few systems have reached full-scale stage, such as OPT and Pelamis. There are three WEC systems classified by working principles [3], including the oscillating water column [4, 5], the oscillating body system [6–9] and the overtopping device [10, 11]. Among the various technologies, the oscillating body systems have been researched widely in the recent years. They generally extract wave power through relative motion between two bodies, almost of them oscillate in only one direction [12, 13]. The power absorption performances of numerous W. Chen F. Gao (&) State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, China e-mail: [email protected] W. Chen e-mail: [email protected] © Springer Nature Singapore Pte Ltd. 2017 X. Zhang et al. (eds.), Mechanism and Machine Science, Lecture Notes in Electrical Engineering 408, DOI 10.1007/978-981-10-2875-5_72
879
880
W. Chen and F. Gao
WECs have been numerically studied [14]. The results show that the capture width ratio of almost existing oscillating systems is not satisfactory. It is well known that the oscillating body has six DOFs in the random ocean waves. When the oscillating body is axisymmetric, only heave, pitch and roll motions have the restoring force (moments), which benefit for the power absorption. Because the restoring force (moments) can make the body itself return to the equilibrium position without external force (moments). However, some mechanisms being able to harvest the three motion’s mechanical energy have not appeared. This paper focuses on the principle of the 3-DOF mechanism for wave energy converter. The power conversion principle of the mechanism is first introduced. Subsequently, the kinematics of the mechanism is derived. The mechanism can absorb and deliver the three motions of the floating body.
2 Conversion Principle The 3-DOF WEC is shown in Fig. 1, and the 3-DOF mechanism for the wave power converter is shown in Fig. 2. b is the wave direction. The oscillating body has three motions in
Data Loading...
