Research On Design Of Tubular Permanent Magnet Linear Generator For The Application Of Wave Power Generation Technology

As a kind of natural energy widely existing in the ocean,wave energy has the wide distribution,characteristics of high energy density,good energy sustainability and so on.The wave power generation system based on linear generator does not need to consider the complex mechanical structure design such as transmission and variable speed,and has the advantages of simple structure,high energy exchange efficiency,convenient maintenance and easy performance design with small volume structure and high performance output.Nowadays,it has been widely concerned by the industry.At present,special-purpose low-power wave energy power generation systems have been promoted and applied to small devices such as navigation lights and observation instruments.Aiming at the requirements of wave power generation on generator output power quality and power density in small self-powered technology,this paper proposes research on the design of high-performance tubular permanent magnet linear generator(TPMLG).In the aspects of working modal,structural optimization and performance analysis,the design experience and criteria of TPMLG suitable for wave power generation technology are systematically discussed.In the structural design of TPMLG,the application environment and structural characteristics are analyzed,and the structure of external long-secondary suits is established as the main scheme of the generator.The slotless structure is adopted to reduce the content and quality of the primary iron core and shorten the effect of the slot effect on the performance of TPMLG to improve the reliability of wave energy applications in complex environments.On the basis of the structural scheme,combined with the application requirements of wave power generation technology,the design guidelines of TPMLG under electromagnetic load,permanent magnet array,winding form,magnetic field check and other factors are discussed emphatically.The finite element analysis(FEM)method is used to complete the design of the TPMLG electromagnetic scheme and optimize the structural parameters.In order to improve the power quality and operation stability,the influence of structural parameters such as radial cross-sectional area ratio,permanent magnet thickness,air gap length,winding radial/axial thickness on electromotive force(EMF)and reluctance force under radial/axial magnetized permanent magnet structure is studied.On this basis,the effective methods to reduce the EMF waveform distortion rate and reluctance force,and then increase the EMF amplitude are discussed to optimize the structural parameters of TPMLG.Meanwhile,the output characteristics of the TPMLG under no load and load conditions are also discussed.Combined with the comparison of structural schemes,the quality analysis of voltage waveforms,and the discussion of operating characteristics with load energy,the guidelines for high power density design of TPMLG are proposed under the constraints of structural parameters such as outer diameter and volume.In the establishment of power generation model,the FEM is used to extract electromagnetic parameters such as TPMLG magnetic flux as input,and combined with the theory of small amplitude wave,a mathematical model of power generation system based on wave motion is established.For the establishment of system generation model,the electromagnetic parameters such as TPMLG's flux are extracted by FEM as input,and the mathematical model of power generation system based on wave motion is established by combining the small amplitude wave theory.This model is used to discuss the influence of wave height and period factors on the output performance of the generator,and the internal laws of the correlation between wave energy wave height and period and generator output performance are summarized,which provides theoretical guidance for the subsequent establishment of accurate system power generation models.