Design And Optimization Of Magnetic-Gear Permanent Magnetic Synchronous Generator

As magnetic gears have great application prospects and research significance in wave power generation,this thesis focuses on the design and optimization of coaxial magnetic gear(CMG)and magnetic-gear permanent magnetic synchronous generator(MG-PMSG).The working principle,electromagnetic modeling,optimized design of CMG and the cogging torque of MG-PMSG are analyzed and discussed in detail.The major investigations include:(1)The operation principle of CMG is given.Firstly,the structure of CMG is introduced.The operation principle of CMG is studied in detail.And the influence of modulating pieces on CMG is analyzed.The air gap magnetic density distribution and torque of CMG are analyzed by finite-element method(FEM),which lays a theoretical foundation for the optimization of CMG.(2)The optimization design of CMG is carried out.The CMG is optimized by using the surface response method and particle swarm optimization(PSO).It is mainly divided into the following steps: determining the initial sample points and designing a set of experiments for the initial sample points;then determining the fitting target and constrained response surface using polynomial function;and then using PSO to find the optimal value of the current response surface.Finally,the optimized CMG is verified by FEM.(3)Basic design of MG-PMSG is made.Firstly,the basic structure and operation principle of MG-PMSG are introduced.Then,the design method of MG-PMSG is given referring to the design experience of traditional permanent magnet synchronous generators.Then,based on FEM,the no-load performance and load performance of MG-PSMG are analyzed.Results show that the design scheme basically meets the requirements.(4)Reduction of cogging torque of MG-PMSG is researched.Firstly,the cogging torque mechanism of MG-PMSG is analyzed.Then,four methods have been applied to minimize the cogging torque,including stator slot width,auxiliary slots in stator,skewed slots stator and Halbach array permanent magnet(PM).Finally,the cogging torque is reduced by the combination of auxiliary slots in stator,skewed slots stator and Halbach array PM.Further,the combination method is compared with the above independent methods,and proved to be more effective for reducing the cogging torque.