Design And Key Technology Of High Power Integrated Generation System For Offshore Wind Power And Ocean Wave Energy

Energy is the development lifeblood of science,technology and economy.Fossil fuels(coal,oil,natural gas)have long been used as the main source of human energy,which promote human progress.However,more and more issues have emerged.Ocean is rich in resources and energy,and ocean energy is renewable and inexhaustible.Full use of marine energy is an important approach to achieve sustainable development.Of all the ocean energy sources,offshore wind power and ocean wave energy are particularly notable.Combined utilization of the two kinds of energy is the research hotspot and frontier in the field of the renewable energy utilization,which has great significance.At present,there is no specific design of the integrated generation system for offshore wind power and ocean wave energy.This article presents the integrated generation system converting the offshore wind power and ocean wave energy by the same medium hydraulic energy into electricity and focuses on the overall design of the integrated generation including the offshore wind turbine generator(WTG),the wave energy converter(WEC),the experiment of the efficiency of the energy conversion device(ECD),the layout topology and parameters of the WECs,the integrated generation unit and the integrated generation farm.Details are as follows:(1)An offshore hydraulic WTG with retractable-blade is designed.The dynamics of the wind power energy conversion system is established.The velocity tracking model of the retractable-blade rotor is established.The relationship between the diameter of the rotor and the wind speeds is established to capture the optimum wind power.The simulation platform is established to analyze the output performance of the hydraulic WTG.(2)Energy absorbing interface of the 3-DOF WEC is designed.The number of DOF of the WEC is determined to be three including heave,pitch and roll.The frequency-domain model of the power absorption of the 3-DOF(degree of freedom)WEC is established.The performances of three geometries including the cone,the cylinder and the hemisphere is compared and the results show that the hemisphere is better to select.The inertial parameters of the hemisphere is matched based on the equal natural frequencies of the heave and pitch(or roll)motions.The adaptability of the different size hemisphere to the different sea states is analyzed,which is able to give a size design reference for engineers.(3)A 3-DOF WEC is invented and the performance is analyzed.The kinematics of the 3-DOF mechanism is derived.The system dynamics of the 3-DOF WEC(wave-oscillating body-3-DOF mechanism-ECDs)is established based on Lagrange's equation and Cummins equation.The relational model of the parameters of the 3-DOF mechanism is established according to the equal natural frequencies of the heave and pitch(roll)motions to design the parameters.The simulation platform is established to analyze the power output performance of the WEC and the results show that the efficiency is over 80%.(4)The power recovery method to test the efficiency of the ECD is proposed.The power recovery method is designed.The simulation platform is established to validate the feasibility of the method.The static mechanical efficiency and volumetric efficiency of the hydraulic cylinder are tested.The power loss by the mechanical transmission of the ECD is tested.The total efficiency of the ECD under various pressures and speeds is tested based on the power recovery method and the results show that the efficiency is about 80%.(5)The layout topology and parameters of the WECs is designed.The frequency-domain power absorption model of the 3-DOF WEC layout is established.The parameters of the triangle layout topology is designed.The relationship between the power absorption performance of the triangle topology and the platform is analyzed and the results show that the existence of the platform has constructive effects on the power absorption.Based on the topology theory,the series topology and parameters consisting of triangle topology units is designed to achieve the optimum factor.(6)The high-power integrated generation principle for offshore wind power and ocean wave energy is proposed to convert the two kinds of irregular and unstable energy by the same medium hydraulic energy into electricity.The 15 MW integrated generation unit consisting of one WTG and three WEC is designed.Finally,the 82 MW integrated plant consisting five units is designed.