Probability Analysis of Transmission Lines Broken and Tower Collapse Caused by Conductor Icing

In a frequent period of extreme climate events, accidents caused by variable weather condition and climate influence to power grid security are increasing. In this paper, regression model between climate elements and ice thickness is established based on micro-climate condition. Ice thickness of each icing process in the district is acquired from the weather data in recent years and corrected by altitude based on regional geographic feature. Gumbel distribution functions are constructed by annual maximum icing thickness and crash probabilities of transmission lines are calculated by their design levels in the service of risk evaluation.