Influence of large-scale ice disaster on transmission system reliability

Large-scale ice disaster has various negative effects on transmission system reliability. According to the weather model, wind speed, rainfall rate and ice load of transmission lines were calculated. In order to analyze the variation of forced outage rate (FOR) in the ice disaster, the relation between ice load and FOR was obtained by curve fitting. For reflecting the stochastic failure of transmission components in the process of ice load increase, a new mixed Monte Carlo simulation method was presented. When components are in the normal state, state sampling is used to judge whether fault occurs on components. When components fail, state duration sampling is used to calculate repair duration time. Simulation of the IEEE RTS-79 system demonstrates that the proposed method is effective. This simulation result also shows that weather parameters and geographical environment may have great influence on transmission system reliability, especially weather moving speed and alignment of transmission lines. ©2011 Chinese Society for Electrical Engineering.