The Load Characteristic Research Of Permanent Magnetic Bearing In Small-Scale Wind Turbine

Because of its low cost,non-pollution,low energy consumption,diversification of configuration and easy to install and maintenance,small-scale wind turbine is particularly suitable for remote pastures,mountainous areas,islands,frontier sentries, weather stations and transit stations where can not set up electrical wire,and also as a landscape installation of street lamps,lawn lamps,parks,villas and so on to solve their issues of power.Due to the start-up frictional resistance of traditional small-scale wind turbine is large,the start-up wind speed needs to reach 3.5m/s and the generation wind speed must reach 4.2m/s,which lead the low wind speed resources of vast region in our country impossible to be developed and utilized.Therefore,the low wind speed generation technology of small-scale wind turbine is an urgent problem need to be solved.The paper puts forward to apply magnetic suspension technology to small-scale wind turbine,replaces traditional mechanical bearing with permanent magnetic bearing,which can eliminate the friction force of beatings radically,so as to reduce the start-up frictional resistance moment of small-scale wind turbine.Permanent magnetic bearing(PMB) is a kind of magnetic suspension beating which makes use of magnetic force produced by permanent magnet itself to make the spindle to be suspended up.For the advantages of small size,simple configuration,no contact,zero wear,low energy consumption,low noise,long life span,high reliability, no lubrication,no oil pollution and so on,PMB has broad application prospects in many areas,and has been recognized as mighty promising new bearing.So it has become more and more important to research their load characteristic.According to the research progress of small-scale wind turbine and Permanent magnetic bearing at home and abroad,based on the former design of magnetic suspension horizontal axis small-scale wind turbine,this paper takes magnetic suspension small-scale wind turbine as the research object.The following questions are studied:1.Compared with active magnetic suspension,passive magnetic suspension (permanent magnetic suspension),hybrid magnetic suspension and superconduct magnetic suspension supporting technology,using permanent magnetic suspension technology,five structural programs of small-scale wind turbine which the spindle is supported by permanent magnet bearings are designed,then their advantages and disadvantages are analyzed; 2.The basic configuration,classification,working principle and the choice of material of permanent magnetic bearing are studied,and the load capacity's mathematical model of axial parallel magnetization radial permanent magnet beatings is established.The load characteristic of axial parallel magnetization permanent magnet bearing,which the magnetic tings are arrayed to axial and radial side-by-side respectively,are studied.Finally,compared with two kinds of radial stiffness that permanent magnet bearings' magnetic rings are arrayed to axial side-by-side,when axial parallel magnetization and 29°rotating magnetization.3.According to the magnetization,the thickness of the magnetic rings and the relationship computed by software ANSYS between the radial force and the axial offset displacement of permanent magnet bearings,the disadvantages of the former design of magnetic suspension small-scale wind turbine are analyzed,and then the unstable reasons of the small-scale wind turbine tester's spindle are found out.Finally, the improved measures for the small-scale wind turbine tester are put forward.4.In accordance with the researchful conclusions of this article,the improved design of magnetic suspension small-scale wind turbine has been completed.