Design And Analysis Of Multi-degree-of-freedom Wave Power Generation System

With the development of science and technology and the improvement of the social modernization,the consumption of primary energy is growing.Traditional energy sources are dried up,which prompts different countries of the world to do more research of the wave energy,wind energy and other renewable energy.It is of great realistic significance for us to solve the power shortage in the coastal area in China,so as to protect the motherland island and to realize the dream of Marine power.In order to solve the problem of low efficiency and poor stability in single-degree-of-freedom wave energy conversion system,a high efficiency multi-degree-of-freedom wave energy converter(MDOF-WEC)is presented based on the analysis of domestic and international research on the status quo of wave power generation technology.The research aiming at improving the abilities of wave capture is carried out.The main research contents include the following four aspects:(1)The application backgrounds of wave energy are described.The development and application status of single-degree-of-freedom wave energy converters and multi-degree-of-freedom ones are explained.The characteristics of wave power and the mechanical model of wave energy converter are presented.(2)Methods of electrical analogue modeling of mechanical system are elaborated.Two equivalent ways from mechanical system to electrical system are used.(3)A single-degree-of-freedom point absorbing WEC and a multi-degree-offreedom one are designed.The force analysis and equivalent circuits are carried out.The wave power transition ratio of the multi-degree-of-freedom converter is proven to be bigger than the single-degree-of-freedom WEC by the simulation and analysis in MATLAB.(4)The completed multiple-degree-of-freedom wave power system is built.Current chopping control(CCC)strategy is applied.Simulation results show that the MDOF-WEC can output desired torque periodically with high efficiency and good adaptability.In addition,the maximum power point tracking(MPPT)is achieved.