The Modeling Of Pelamis Wave Energy Converter And Control Strategy Study On Multi-cylinder Hydraulic System

With the increasing use of the present social resources,non-renewable energyresource is at risk. So it’s imperativeto tap the ocean resource.The ocean resource is akind of reproducible green resource. Our country has large area ocean and abundantocean resources.It will have great social value and economic value to develop a kind ofefficient and dependable sea wave energy device to produce electricity. Pelamis waveenergy converter is currently the world’s most advanced wave power systems, the use ofarticulated tandem floats produce relative rotation between buoys, then drive articulatedhydraulic cylinder hydraulic power generation.This paper mainly studys Pelamis waveenergy converter and the control strategy of assembly cylinder hydraulic press.The main energy-converting component of Pelamis wave energy converter ispontoon. The hydraulic cylinder’s movement is determined by the pontoon’s movementwhich is influenced by hydraulic cylinder’s acting force. This is coupling process. Justbecause of this process,we can get the changing conditions respectively as long ascalculating pontoon’s movements and the control strategy of the hydraulic system at thesame time.Firstly, this article establishs a Pelamis wave energy converter mathematical model.Including:1) Using geometry and calculus theory, this article analysises of the seaserpent type wave transducer transducer components main pontoon in the waves of theforce;2) Using Lagrange equations and virtual work principle, this article establishs abuoy in waves kinetic model.According to the above model,using classical4order fairly Runge-kutta methodand getting numerical integral of lagrauge’sequation,we can conclude the pontoon’sstress and law ofmotion.Finally,we can analyze pontoon’s parameter and sea waveparameter’s influence on pontoon’s energy. We change the quality of floats and momentof inertia, floats capable of operating in a resonance state. With the increase of waveenergy, the energy transducer gradually increasing trend in the flat, is conducive to thesurvival of the transducer.In order to improve the efficiency of energy absorption, using a multi-cylinderhydraulic system for energy conversion. Two single rod hydraulic cylinder four workingchambers respectively, through separate control valve and pressure accumulator or lowpressure accumulator connected to pass, resulting in a series of changes in the actualactive area.That is to make the hydraulic system have more absorbing energy throughchanging the total active area of hydraulic cylinder based on the change of external conditions. Angular velocity were investigated under floats, buoys and floats rotationalkinetic moments practical effect of the hydraulic cylinder area selection control strategy,The results show that the energy absorption efficiency can greatly increase, as comparedwith the cylinder combination is not used, efficiency is improved by50%. In addition,the role of the largest area of the hydraulic cylinder, different wave conditions on theenergy absorption efficiency of capture. The results show that, for a particular waveconditions, there is an optimum hydraulic cylinder maximum effect size for maximumenergy. Waves wave height, period increases, the hydraulic system can increase theabsorption decreases and leveled off, indicating that the sea serpent-type wave powersystems to survive the harsh sea conditions are good.