Incremental Harmonic Balance Method For Galloping Of Iced Conductor

Galloping of an overhead, iced conductor is a kind of self-excited vibration with thefeature of high amplitude and low frequency, which is caused by steady side wind. Seriousdamage in the electrical power supply will be produced due to the inability to icedconductor galloping, such as conductors break, transmission tower collapse and the failureof insulator strings and other tower components. Therefore, it is very essential to study thedynamic property to galloping of the iced conductor.In this paper, the conductor governing differential equation have been derived byusing Hamilton principle based on cable model, and its static configuration and innertension can be also obtained. The displacement is formed by increment，the mass matrixand stiffness matrix of the element can be derived by the conductor displacement lineargoverning differential equations. The constraining conditions between sub-conductorsimposed by spacers are considered in the formulation of the element. Futher, the gallopingof iced transmission lines was a strongly nonlinear vibration. The incremental harmonicbalance method was used to establish the finite element model and balanced equation oficed conductor vibration. Then, vibration balanced equations were solved, which includethe square and cubic stiffness items, square and cubic viscous damping. The vibrationprocess was decomposited as a transient incremental continuous vibration process. Wavefrequency and amplitude were obtained, and then the analytical expressions of equationwere solved.This set of galloping analyse methed is proved to be reliable and can be applied toengineering practice, as a guide to evaluate the security and reliability of the transmissionline.