Research On Nonlinear Vibration Characteristics Of Two Spans Transmission Lines Coupled System

With the rapid development of economy and society, the requirement ofelectric power is getting more and more. National "Twelfth Five-Year" Planoutline for development tendency of the electric power is a gradual change fromnationwide electric power exchange network to Intelligent electric network. Thetrustiness, safety and efficiency of electric power supply is not only related to thenational economic development and the social stabilization,but also a materialand technical basis for keeping normal life and productive activities smothly.Ice-covered transmission line and ice-shedding do fatal damage to electric powersystem. It is necessary to study the characteristics of static and dynamics in theprocess of ice-covering and ice-shedding for us to strengthen the ability ofresisting disasters. Study on nonlinear vibration in-plane of transmission line isstill far from completion, mechanics analysis model is not abundant enough.Based on this, on the basis of isolated transmission line’s nonlinear dynamics, themechanical model of nonlinear vibration in-plane for two-transmission line systemwere created, Research about coupling mechanism of transmission line. Thediscussion centered around this subject.(1) By studying parts of transmission line,we can acquire the mechanicalmodel of nonlinear vibration in-plane for two-transmission line system.Thecatenary and parabola formula for initial shape of transmission line have beensummarized under the action of static loads.(2) Two-span transmission line strain section as research object,using thesimplified initial shape formula, we can get a set of ordinary different equationsof two-span transmission line by applying Newton’s law and Galerkin method.(3) Displacement time histories of vibrating system are acquired in different structureand initial conditions of the system by solving nonlinear equations. The numerical resultsreveal that the coupled effect of two-span transmission line is notable.,and throughcomparison,we find effective ways to reduce or avoid in-plane vibration of two-spantransmission line coupled system. Finally,we explore internal resonance when the naturalfrequency ratios of the two spans transmission lines approach1:1or2:1.