| In recent years,with the increasingly serious air pollution,the exploitation of traditional fossil energy has been reduced step by step and the proportion of clean energy in our country has been increased year by year.However,the wind is inexhaustible clean energy,it has been become extremely urgent how to full utilize wind energy in wind power industry.The wind turbine is an important mechanical equipment for capturing wind energy,which not only can convert the wind in natural into the electric energy required in daily life,but also its capability directly influences the wind power conversion efficiency.With the rapid development of wind power industry in the past 40 years,at present,all kinds of wind turbines have appeared except for the traditional horizontal axis wind turbines(HAWTs).In wind power industry,the vertical axis wind turbines(VAWTs)have become another development direction because of their unique performance advantages,such as simple structure,no need to align wind direction,no speed-up gearbox,easily start by itself,flexible installation locations,convenient maintenance and low cost etc.In the future,the general wind power trend must be primary by the large-scale HAWTs,and the small-scale VAWTs are auxiliary.HAWTs generate power into the grid,while off-grid operation for VAWTs whose generation and use are carried out simultaneously.Finally,the supply and demand balance will be formed in wind power system.Based on the novel Senegal type VAWTs,taking the electromagnetic field and fluid field of wind turbine system as two research directions,the total wind power system is analyzed by the theoretical derivation and the finite element simulation in this paper.In the electromagnetic aspect of the wind turbine system,based on definite integral differential method,the basic electromagnetic relation of the disk generator is mainly analyzed,simultaneously,the electromagnetic torque and power fundamental equations is derived and achieved.Finally,a main flux path is determined for the disk generator.Considering from practical application,according to the basic characteristics of the disc generator,a number of its parameters are selected and determined such as the rated voltage,the rated power,the optimum tooth-slot number,the pole number,the dimensions and shapes of stator and rotor,etc.Therefore,a novel coreless wind-driven generator with magnetic concentrator is presented in this paper.Based on the 3D magnetic module for the finite element software Ansoft Maxwell 16.0,the static and no load transient electromagnetic characteristics for the disk generator are analyzed.Then,the transient load characteristics are also analyzed by considering the storage batteries as the generator load,in this way,the relations curve of various parameters are obtained.In the fluid field aspect of the wind turbine system,based on the Bates theory and the blade element theory,the Computational Fluid Dynamics(CFD)to the wind turbine is analyzed,in addition,the turbine's maximum power and force for the wind turbine are derived.By means of the CFD,the overall fluid field of the VAWTs is calculated and analyzed by importing wind turbine model mentioned in this paper into fluid field module ANSYS CFX of ANSYS Workbench 15.0.After,the optimum turbine structure and the wake field at different locations for the wind turbines are obtained by simulation.Finally,the optimal interval distance for multiple units are determined according to the wake distribution characteristics of single unit,after,a small-scale wind farm is designed including ten Senegal type VAWTs.Through the comprehensive fluid field simulation for wind farm,the optimal layout of the VAWTs units is determined.Taking Senegal type VAWTs as thread,the total wind turbine system is comprehensively analyzed from the two view of electromagnetism and fluid in this paper.These results can be used as reference for the research and development of this kind of VAWTs. |
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