Vibration Model Of Composite Insulator Beam With Stepped Cross-Section Based On State Space Method

Insulators are the key components connecting wires and towers in transmission lines,and their structural safety directly affects the power supply safety of transmission lines.Silicone rubber composite insulators stand out for their excellent anti-pollution flashover performance,lightweight structure and low maintenance cost.In order to effectively detect the working state of the composite insulator in the project and prolong the working life of the insulator.Therefore,it is very important in engineering to quickly calculate the natural frequency of vibration of composite insulators.We takes the silicone rubber composite insulator as the main research object,carries out the mathematical theory derivation analysis,the method of combining finite element numerical simulation and experimental research,specifically studies the vibration model of the variable cross-section beam of the composite insulator,and compiles the insulator vibration frequency calculation program.The factors affecting the vibration frequency of composite insulators are explored.The main work and conclusions of this paper are summarized as follows:(1)Based on the principle of equivalent stiffness,a simplified model of the composite insulator cylindrical variable-section beam is established.According to the basic theory of elastic mechanics,a system of calculating the vibration frequency of composite insulator beams with variable cross-section based on the state space method is derived and established,and the JCM method is used to improve the solution accuracy.The equation system can accurately simulate the different crosssectional properties and material parameters of each part of the composite insulator,and consider the complex boundary conditions at both ends in detail,providing theoretical support for measuring the natural frequency of composite insulator vibration in engineering.(2)A quick calculation program of the natural frequency of the composite insulator was written using MATLAB software,and the natural frequency of the composite insulator was measured by simulating the working environment of the composite insulator by using the ABAQUS finite element analysis software.By building a composite insulator vibration frequency measurement experimental bench,measuring the composite insulator vibration natural frequency,and comparing the experimental results with the program calculation results,the correctness of the composite insulator vibration frequency calculation equation based on the state space method is verified.(3)Combined with relevant examples,the effects of composite insulator axial tensile force,section flexural stiffness and end boundary conditions on the vibration frequency of the insulator are analyzed.The research results show that the vibration frequency of the composite insulator increases with the increase of the axial tensile force,and the vibration fundamental frequency of the insulator increases at the same time with the increase of stiffness,and the vibration frequency of the shorter composite insulator is relatively long.The composite insulator is more affected by the boundary conditions.