Ice Storm Impact on Power System Reliability

Ice storms are freezing rain that coats everything in ice, often in combination with heavy wind. The aim of the methods developed in this paper is to estimate the risk of failure due to ice storms. This includes a severe weather model, a new method for choosing weather parameters and a component vulnerability model. The weather model is based on how a low pressure behaves and consists of functions that describe the wind and precipitation parts of the weather. An ice accretion model is used to estimate the ice loads. The method for choosing weather parameters is useful for Monte Carlo simulations where the effects of many different weather situations are studied. In the stochastic component vulnerability model the failure rates are based on how an increased ice load influences the critical wind. Swedish weather conditions and transmission components are used in the case study and the loads and their impact are estimated for many different weather situations.