Nonlinear Modeling And Dynamic Characteristics Of Long-span Suspended Transmission Lines

Transmission lines as an important part of the grid,with the high-voltage power grid to develop,will move toward the large span,flexibility,light and low damping direction.However,it is because of these characteristics,the transmission line in the wind,rain and snow and other external conditions under the action of a substantial vibration,thus the construction and operation of the power grid adversely affected.Therefore,it is of great significance to study the modeling theory and nonlinear dynamic characteristics of large span transmission lines to guide the design of large span transmission system.Based on the Hamilton variational principle and the boundary condition and connection condition,a fine dynamic model of double span and multi-span transmission line system is established.The Galerkin discretization method and multi-scale perturbation method are used to solve the problem.The nonlinear resonance response of large span transmission line is analyzed.Specific work is as follows:Based on the theory of suspension structure,the differential equation of single-span transmission line is deduced by Hamilton variational principle.The multi-frequency excitation is obtained by Galerkin method and multi-scale method.The theoretical and numerical methods are analyzed by theoretical and numerical methods.Primary resonance and 1/3 subharmonic resonance response.Based on the single-span transmission line model,the nonlinear differential equations of the two-span transmission lines are deduced according to the boundary conditions and the continuous conditions.The linearization system is obtained by reducing the dimension reduction,and the in-plane and out-of-plane The natural frequency of the transcendental equation,and then get the corresponding vibration expression.At the same time,the transmission line modeling theory is further extended to multi-span transmission line system,which lays the theoretical foundation for the design of large-span transmission line network.The Galerkin method is used to separate the continuous system into the ordinary differential dynamic system,and then the multiresolution method is used to solve the main resonance response of the two-span transmission line system.At the same time,the 1:1 internal resonance between different modes is analyzed,and the stability of the solution is studied.