Risk Assessment of Cascading Failures in the Transmission Grid Considering Uncertainties in Short-term Operational Planning

Abstract

The uncertainties of load and infeed from renewable energy sources as well as a higher utilization of the transmission grid due to increasing transmission distances lead to lower security margins in grid operation. For that reason, recent methodologies in transmission grid operational planning have to be challenged. In this paper a methodology is introduced using an analytical approach for the simulation of a probabilistic load flow. This load flow is combined with a simulation of cascading failures. The aim of the methodology described in this paper is the consideration of uncertainties from load and infeed as well as quantifying the impact of outages like cascading failures in short-term operational planning. The exemplary results show that information based on the probabilistic load flow can be generated. This information can be helpful in short-term operational grid planning and might be used in congestion management in the future. Furthermore, the modelling of cascading failures in combination with results of the probabilistic load flow enables the possibility of a stochastic description of the risk of unlikely cascading failures.