Researchand Designof Halbach Magnetic Gear Wind Power Generator

Halbach magnetic gear wind power generator based on magnetic gear transmission is utilized to solve the mismatch problem between the generator and the speed of wind turbine in traditional wind power system by applying magnetic field modulated magnetic gear to wind power system.Adopting this structure,not only the construction of wind power system is optimized,but also the deficiencies of mechanical gearbox are remedied,consequently,the validity and stability of the entire system are consolidated.In this thesis,a novel Halbach magnetic gear for wind power generator is designed by combining the traditional structure of magnetic field modulated magnetic gear.Also,the parameters and characteristics of magnetic gear for wind power generator are researched.Firstly,basic structure and operation principle of Halbach array are analyzed.It is compared with conventional radial magnetization by using finite element method,thus the advantages of Halbach array are obtained.In order to calculate the output torque and analyze the electromagnetic field,finite element method and the analysis software JMAG based on the finite element are introduced in this thesis.Secondly,a Halbach magnetic gear with simple structure for wind power generator is developed.Besides,the optimization of Halbach magnetic gear is conducted and the influences on torque and EMF caused by the structure parameters of Halbach magnetic gear are analyzed.Also,each parameter model of Halbach magnetic gear is simulated in JMAG,by analyzing the simulation structure of each parameter model,the optimal result is selected as the optimum proportion for Halbach magnetic gear wind power generator.Thirdly,the structure of the motor is determined based on the optimization of Halbach magnetic gear for wind power generator.Two-dimensional finite element model of Halbach magnetic gear is built and simulated with finite element method in JMAG.This thesis mainly focuses on the analysis of air gap magnetic field,static torque,steady torque,cogging torque and EMF.Lastly,in order to reduce manufacturing costs of motor and increase the utilization of permanent magnet,three modified Halbach magnetic gears for wind power generator are developed on the basis of original motor design.Future research wok is proposed by comparing torque characteristics of the four motors.