Research On Vertical Axis Halbach Array Coreless Axial Flux Wind Turbine

Energy is an important foundation for the continuous development of society.With the continuous decrease of fossil energy and the increasingly serious environmental problems,new clean energy is required to replace traditional fossil energy.Among many new energy sources,wind energy has many advantages.In order to make full use of wind energy,small vertical axis wind turbines have emerged as the times require,which can provide power for road lighting,household electricity and remote areas.Compared with large wind turbines,small generators are easy to install and maintain.The generators adopt axial flux permanent magnet synchronous generators without iron core,which can eliminate cogging torque and iron consumption,has no iron consumption and high efficiency,it can realize "light wind start,light wind power generation".Because the air gap magnetic field of the axial flux permanent magnet motor is three-dimensional distribution,it can not be analyzed by two-dimensional finite element method alone.Aiming at the problem that three-dimensional solution needs a lot of time,the air gap magnetic density of the Halbach permanent magnet array generator and the cut cake type permanent magnet generator is solved by analytic method to reduce the solution time,and is compared with the three-dimensional finite element method,the parameters of the two generators are changed respectively,and the influence of different parameters on the voltage total harmonic distortion rate and torque of the generator is analyzed.In view of the problem that the voltage harmonic content of the axial flux permanent magnet synchronous generator is large,according to the basic electromagnetic theory of the traditional motor,this paper preliminarily determines the parameters of the Halbach permanent magnet array coreless axial flux permanent magnet synchronous generator.Because of the interaction between the parameters of the generator,in order to reduce the harmonic content of voltage,Taguchi-Response surface method is used to optimize the pole arc coefficient,the thickness of permanent magnet,the width of coil and the length of air gap,to improve the efficiency of generator,and to select the voltage amplitude reasonably.In order to study the no-load and load characteristics of the generator,the Taguchi method is used to analyze the voltage regulation rate and the voltage harmonic distortion rate of the generator based on the optimized generator.Finally,the parameters of the generator are determined to improve the performance of the generator.According to the parameters of the optimized generator,a 300 W Halbach permanent magnet array coreless axial flux permanent magnet synchronous generator is fabricated,and an experimental test platform is built.The no-load characteristics and load characteristics of the generator are tested by the driving of the prime mover.The results show that the output characteristics of the generator are stable and meet the basic design requirements.