Research On Control Strategy Of Hydraulic System In Three Buoy Wave Power Generation Device

With the development of society, the consumption of energy is increasingly,fossil fuels are also sharply reduced. In the long run, it will cause a series of socialproblems. Now, people are looking for the energy which is clean and renewable. Ifit can be transformed into electricity daily required, then it will have great socialand economic value. The coastline of country is long and narrow, and sea area isvery broad, Therefore, it is important to develop a device which can convert Marineenergy into the energy that can be utilized by people.Raft-style wave power device uses three buoies as its absorb parts, the buoies isconnected with the cylinder. In the process of the waves cross through the bodies, itcause the movement on the buoies, so the hydraulic system began to absorb energy;The force from the Hydraulic cylinder operate on the buoy’s body, then the forcecaused attenuation of the ocean wave energy. The two processes are coupled to eachother.In order to absorb the energy of waves maximum, it is necessary to analyzethe effection of hydraulic system control strategy for energy absorption efficiency.Firstly, discusses the working principle of the wave converter, analyze the forceof barrel caused by waves under different moment based on two-dimensional space;Obtained the force and moment caused by hydraulic cylinder in different times andthe influencing factors of body spinning. Established the dynamic model of theconverter according to use dynamic principles of rigid body and the secondLagrange equation. Obtained space state equation of dynamic model with applyingRK method.Research the velocity potential function and the control equation of the two-dimensional linear wave; Analyzed the influence of the parameters act on waves;meshing the area of converter model; Generating coupling simulation model of themodel and wave and set up the simulation parameter; Simulated converter modelunder no action of the hydraulic system; Acquired the motion and force andmoment of barrels.Outlined the control strategy principle of hydraulic system and methods on how tocombine effective area, Use hydraulic system in the form of composite cylinder toform different effective action area, combined five kinds of effective area, Researchthe control process of the hydraulic system and method about chose control volume,Using the force casued by wave and energy barrels have to switch effective area ofthe hydraulic system; Study absorption efficiency of the hydraulic system, obtain conclusion that the core of control of the hydraulic system is the matching betweeneffective area and speed of the piston; analyzes the absorption efficiency under twocontrol methods; Research absorption efficiency when the effective area ofhydraulic system is different, the results show that there is a best proportion area tomake sure the highest absorb efficiency; Study the absorption efficiency when thefront and back area ratio is different; research the effection of moment on energyabsorption efficiency; at last, research the the influence of height and length ofwave on energy absorption, it shows the height of wave should be increasedappropriately and length of buoy need to the made slightly more than half length ofwave if want to improve the absorption efficiency.