Study On Electro-hydraulic Control System Of Marine Current Turbines

The marine current energy resources will supply a significant fraction of future electricity needs in the 21^st century. If successfully developed, the marine current energy resources will become a major new industry to produce clean power and promote development of the national economic. This paper decribes the hydraulic power take-off system employed in the marine current turbines energy converter and pitch control system of the marine current turbines.The first chapter in this thesis generally introduces the prospect of the marine current energy resources and the development of the marine current turbines base on relevant publications search and investigation. Then the paper focus on the development of energy converter and power control. At last, the project signigficance and main research contents are presented.The second chapter introduces the basic theory of the marine current turbines. Lift coefficient, drag coefficient, pitch moment coefficient and so on are analyzed. Then simulation of lift and drag coefficient and cabitation has been done on the Fluent software.The second chapter simply introduces the working principles of marine current turbines. Then the working principles of power take-off system employed in the marine current turbines energy converter are discussed and analyzed. And the chapter focus on the introduction of design of hydraulic take-off system , generator and load controller.In the fourth chaper, the mathematicai medels of project system have been established, and simulation has been done on the Simulink environment of Matlab software kits. The simulation focus on control strategy of avariable-speed constant-frequency and ISC.The fifth chaper introduces the technology of avariable-picth marine current turbines which can trach current and control pitch. The chaper focus on the introducture design of pitch-control system, calculation of key parameter.The sixth chaper introduces the avariable-picth marine current turbines semi-physical simulation test-bed. Then simulation of pitch-control system has been done on semi-physical simulation test-bed.At last, the main achievements of this thesis are mentioned, the directions for further working are also pointed out.