Extension of power system early-warning defense schemes by integrating typhoon information

Typhoon disasters usually cause faults to power grids, such as broken lines, collapsed towers, windage yaw flashover and so on. In severe situations, they may result in group-occurring faults and lead blackout to power systems. As a result, it is very necessary to extend the power system early-warning defense schemes, from the traditionally general anticipated fault set to group-occurring faults caused by extreme external disasters. After reviewing the operation status and defense measures of power system under typhoon hazards, current situation of typhoon forecasting and the characteristics of typhoon disasters, a method to predict the failure probability of transmission lines under the typhoon disasters based on the investigation of ways and mechanisms of typhoon disasters that affect the power system is proposed in this paper. Firstly, transmission lines are classified by their geographic features and environmental characteristics based on the geographic information, then their dynamic variables are evaluated, including the length of lines in the wind circles, lasting time, average rainfall and so on. Secondly, wind speed and wind direction can be computed on the basis of typhoon forecast information, and are revised in the light of the particular geographic features and environmental characteristics. In order to calculate the probability of broken lines, collapsed towers, windage yaw flashover and lines covered by foreign bodies, the probability models are developed in term of fuzzy mathematics. Finally, the failure probability of the entire transmission line can be attained by making use of the computed probability of the classified lines. According to the probability, all lines whose failure probabilities are larger than the threshold value are selected out. And then these information data are applied to the risk set of the facilities of the Wide ARea Monitoring Analysis Protection and control system (WARMAP). (7 pages)