Risk Assessment of Cascading Failures in Power Systems with Increasing Wind Penetration

The ever-growing penetration of renewable based gen-eration is leading to significant increases in the risk of cascading failures in low-inertia, and interconnection-rich, power systems. This paper proposes a framework for quantifying the risk of cas-cading failures in renewable-rich power systems with fast fre-quency response (FFR) services. This is achieved by developing a novel time-based dynamic model of cascading failures to capture the transient behaviours of the system response and quantify the risk of blackout. This dynamic cascading failure model is comple-mented by unit commitment for representative dispatch and in-cludes the provision of FFR. The proposed framework is illus-trated using a modified version of the Illinois 200-bus synthetic system. As key outputs, the results emphasize the importance of accurate modelling of ancillary services associated with fre-quency regulation in cascading failure analysis, and indicate that increased wind penetration can lead to a higher probability of power outages. Adopting FFR services can help to mitigate the cascading risk but may introduce rotor angle instability issues.