Mid-short-term risk assessment of power systems considering impact of external environment

Ice flashover, lightning flashover and bird damage are the main reasons that cause transmission facility failure. The impact of these environmental factors on the operational risk levels of power systems should be taken into account in power system maintenance scheduling and operation planning. This paper studies the mid-short-term risk assessment methodology considering the impact of the external environment. The relationship model between natural disasters and transmission lines is presented. The conditional outage rate model and the sampling technique are then proposed considering the correlated outage of multiple transmission lines when a disaster happens. The framework of the mid-short-term risk assessment model is outlined. A test case of Jiangxi provincial power grid validates the proposed model. The results show that the model can quantify the impact of disasters on the forced outage rate of transmission component and their outage correlation, and thus effectively revealing the mid-short-term risk of power systems. The model can facilitate a more strategic decision-making on maintenance scheduling and operation planning of power systems.