Stability analysis and dynamic equilibrium of a Kuroshio generator system

• Main Authors: Hsing-Cheng Yu, Yi-An Chen, Young-Zehr Kehr
• Format: Article
• Language: English
• Published: JVE International 2016-03-01
• Series: Journal of Vibroengineering
• Subjects: dynamic equilibrium; Kuroshio generator; ocean energy; stability analysis
• Online Access: https://www.jvejournals.com/article/16749

Global resources for conventional energy are currently being exhausted, and several countries worldwide are attempting to develop renewable energy. Current generator systems are a subject of ocean power research. This paper proposes a novel design of a Kuroshio generator system (KGS) that is suitable for the maritime environment of Taiwan (i.e., an average flow velocity of the Kuroshio Current is 1.45 m/s and the flow can be accelerated on Keelung Sill with a depth of 50-250 m). The KGS combined a reliable cable design and simple anchor system at sea and was not affected by motion changes of rotation axes in yaw and roll by way of an appropriate rudder design. An intuitive simulation method applied using MapleSim software was used to create a rigid KGS model. Different modeling frameworks for varied cable design and joint positions were adjusted to meet system requirements. An intuitive simulation method applied using MapleSim software was used to create a rigid KGS model. Different modeling frameworks for varied cable design and joint positions were adjusted to meet system requirements. The stability analysis was performed to determine dynamic equilibrium and motion behavior of the KGS and the combined cable design. The optimal spring stiffness and damper coefficient of polyester fibers were set as 5×105 N/m and 3×105 N∙s/m in the simulation, respectively. Furthermore, to achieve the torque equilibrium in pitch motion of the KGS, an optimal joint position that was relative to the leading infraedge of the outer duct was set at 2.2 m along the negative surge axis according to their responses in the simulation. Finally, the force and torque generated by the hydrodynamic effect in the KGS and the estimated specifications of a direct-drive permanent magnet generator equipped with an external rotor were imported into the simulation. Consequently, the motion ranges of translation axes in surge and heave were converged within 0.5 m, and the estimated output power in the KGS exceeded 54.8 kW.