Design Of Cylindrical Permanent Magnet Linear Generator Used In Ocean Wave Generation Based On Level-Set Method

This paper focuses on the design of cylindrical permanent magnet linear generator(PMLG).The investigation of topology optimization based on Level-Set method is a comprehensive design issue of electromagnetic inverse problem.By seeking to better electromagnetic structure which may contain holes with different quantities,sizes,and positions,the topology optimization method can achieve a certain optimal performance under a series of constraint conditions.In this paper,the cylindrical permanent magnet linear generator applied in ocean wave generation is the major investigation objective.The running principle,electromagnetic modeling,and theories of level-set and curve evolution are all be introduced in detail.Besides,the process of topology evolution of permanent magnet is considered as the most important content around which an abundant analyses and discussions are made.The major investigations include:(1)The basic theory of level-set method.The principle of curve evolution is introduced first.The establishment,solution,and initialization of level-set function are all be analyzed at length second.The advantages of level-set method are summarized finally.(2)The design of cylindrical PMLG.The primary structure and running principle of PMLG is presented first.By referring to the traditional permanent magnet machine design example,the specific steps of PMLG design method are introduced in detail.Then the finite-element method(FEM)is illustrated and the relevant equations of potential function and boundary condition function are both derived.Finally,FEM is applied to the designed PMLG by ANSYS Maxwell.(3)Topology optimization of permanent magnet of PMLG.The major steps include: setting the objective air gap magnetic field and selecting proper measure points;performing topology evolution on the permanent magnet based on level-set function;using FEM to analyze the PMLG with the updated PM by ANSYS Maxwell;making a judgment of the validity of the final design result by making comparisons and contrast.