DYNAMIC RESPONSE ANALYSIS OF MULTI-SPAN TRANSMISSION LINE TO ICE-SHEDDING SHOCK

A finite element method is presented to analyze the dynamic responses of multi-span transmission lines to ice-shedding from conductors. While the isoparametric cable elements with parabolic shape functions are used to model the conductors of multi-span transmission lines and ice, spatial spar elements are used for the insulators. The impact load effects due to ice-shedding process are considered in the dynamic analysis by employing an element birth and death method. The implicit time integration algorithm considering geometric nonlinearity is utilized to solve the nonlinear dynamic equilibrium equations. The convergence difficulty of the implicit algorithm is overcome by using adaptive time steps. Two ice-shedding cases from one span and three spans are simulated to investigate the influences of a number of factors to the ice-shedding shock, such as ice-shedding spans, the tension of a conductor, the distance of a span and the length of a insulator string.