Study On The Technology Of Wave Power Generation By Oscillating Float

Since the reform and opening up,with the rapid economic growth,the human beings are faced with the situation of excessive consumption of energy.In order to effectively alleviate the shortage of resources,the development and utilization of renewable energy has been vigorously promoted,such as wind energy and solar energy.Wind power and photovoltaic have a more widely distributed,the ocean energy with greater energy density is still very backward comparatively.Wave power generation,which utilized the ocean wave kinetic energy,can effectively ease the energy supply,promote the development of marine resources,improve the environment,promote economic growth and employment.In this paper,the structure and the realization of the maximum wave energy capture control strategy of the oscillating float wave generator are studied.Firstly,motion characteristics of the float is analyzed which cause by the ocean wave force,three kinds of calculation methods are introduced in this paper.Particularly,the Froude-Krylov theory method is utilized to calculate the vertical wave force,which lays the theoretical foundation for the stress analysis of the traditional float;Secondly,the structure analysis and mathematical modeling of traditional direct drive oscillation float type wave power device,lay a model foundation for the proposed new float;put forward a double degree of freedom closed float structure,based on the structural analysis,mathematical modeling,analyzes the motion characteristics,and compared with the traditional float,the conclusion that the new float is suitable for large sea wave frequency and have an advantages of easy control is obtained.These theories lay the foundation of simulation and application for the next chapter.Thirdly,simulation modeling of the wave power generation system is presented.The modeling results of the new double degree of freedom float show that the larger wave frequency the higher the float power capture.Different spring and mass are discussed under the variable wave frequencies;Through introduces the motor coordinate transformation,the mathematical modeling and simulation analysis of the permanent magnet synchronous generator are built by the Matlab software;A load control method is proposed.The controllable three-phase bridge with DC power supply mode is supplied to simulate the load,which can adjust the variable load via the control switch.Through the detection of generator output power to observe the relationship between local search method and the load,the simulation results show that only one output load resistance can achieve the maximum power.Then,the paper put forward a maximum power point tracking(MPPT)control method which based on the buck circuit.Based on the analysis of the buck circuit,obtained the conclusion the we can change the load by changing the switch duty cycle.The hill-climbing method is used to keep the maximum power point tracking,and the simulation results by matlab software show that the MPPT algorithm with the buck circuit is practical.Finally,an experimental platform is built.The motion characteristics of ocean wave is simulated by means of mechanical device.Test the effect of spring and mass on the average power,then the influence of the variable resistance to the average power is verified under the situation of the optimal parameters.