Modal Analysis And Structural Optimization Of Inductive Energy Transfer Rotary Transformer

Brush slip ring is an important part of the traditional doubly fed induction motor,but it increases the possibility of accidents when the mechanical structure is working,and thus increases the maintenance cost.Therefore,the traditional doubly fed induction motor’s de brushing has become the focus of many scholars.The primary and secondary windings of the rotary transformer studied in this paper are not in direct contact with each other.The primary and secondary sides of the resolver can not only ensure the relative rotation,but also transmit the energy.Therefore,the rotary transformer can replace the brush slip ring to achieve the goal of de brushing.There is air gap in the structure of the rotary transformer.When the rotary transformer is working,the air gap magnetic field acts on the stator core to generate electromagnetic exciting force,and then the vibration noise occurs.In the field of electrical machinery,many scholars have carried out in-depth discussion on its vibration and noise;and the rotary transformer studied in this paper is a new structure designed and developed by Shandong University,which needs to be studied on its vibration and noise.This paper analyzes the radial electromagnetic force and modal analysis of the rotary transformer designed and developed by Shandong University,studies the relationship between each structural parameter of the rotary transformer and its vibration and noise,and optimizes the structure of the related parameters of the resolver to further improve the rotary transformer performance.This paper systematically analyzes the vibration and noise of a rotary transformer based on energy transmission.The main work and innovations are as follows:1)Analysis of the radial electromagnetic force of the rotary transformer-Radial electromagnetic force is the main excitation source for the electromagnetic vibration of the transformer.This paper firstly studies the radial electromagnetic force on the inner surface of the stator of the rotary transformer.Starting from the air gap magnetic field of the rotary transformer,the Maxwell stress equation is used to obtain the radial electromagnetic force waves per unit area of the stator inner surface.,And further conducted a finite element simulation analysis of the air gap magnetic field and radial electromagnetic force of the rotary transformer under no-load conditions;The change of electromagnetic force was studied,which laid the foundation for the next optimization work.2)Modal characteristics of rotary transformer.In this paper,with the help of three-dimensional finite element simulation analysis method,modal analysis is carried out from two aspects of stator and rotor.First of all,the systematic study of the influence of various structural components and material parameters of the stator on the stator modals was carried out.ANSYS was used to establish a three-dimensional dynamic analysis model of the rotary transformer.And frequency,and compared with the calculation results of ordinary analytical methods to verify the integrity of the finite element results,and analyzes the effects of various material parameters of the stator core on the mode and frequency of the stator mode;separately study each part of the rotary transformer(winding,The effect of the casing and end cover on the structural modals is simulated to determine the frequency of each mode of the rotary transformer,which provides a reference and basis for the research on the vibration of the rotary transformer.Based on the three-dimensional physical model of the rotor,a three-dimensional model of the rotary transformer rotor is established.In the free state without any structural constraints,the influence of each structural component of the rotor on its various modal frequencies is analyzed;then the structural parameters of the rotor on the rotary transformer are studied The effect of rotor modal frequency.The research on the rotary transformer rotor parameters provides some theoretical guidance for the rotary transformer rotor design.3)Optimize the structure of the rotary transformer.Based on the goal of reducing the vibration and noise of the rotary transformer,this paper starts with the structure optimization of the rotary transformer,combines the characteristics and requirements of the multi-objective optimization design,introduces the Taguchi method and establishes the horizontal factor orthogonal vector based on the accurate calculation of the FEA analysis method Table,which greatly improves the calculation efficiency of the traditional finite element method and solves the problem of low operation efficiency of the traditional FEA method.The optimal structural parameter combination of the rotary transformer lays a theoretical foundation for subsequent structural optimization and experimental testing of the rotary transformer.