Forced-self-excited system of iced transmission lines under planar harmonic excitations

This work involved analyzing the self-excited and forced vibrations of iced transmission lines. By introducing an external excitation load, effect dynamic wind on nonlinear vibration equations was reflected by vertical aerodynamic force. The approximate analytic solution non-resonance forced-self-excited system obtained using multiple scale method. With increase in amplitude, nonlinearity enhanced, experienced three stages—namely, vibration, superposition forms vibrations, controlled damping. Among these, accuracy decreased with strength variations. When amplitude greater than critical value, quenching phenomenon appeared system, discriminant formula derived this work. In addition, third-order Galerkin method, which considered small sag effect, used to discretize galloping governing equation. response (principal resonance, harmonic resonance) analyzed time history displacement curves phase diagrams. conclusions may contribute practical engineering More importantly, as a combination Duffing equation Rayleigh equation, have high theoretical research value.