Cascading-Aware Deployment of Decentralized Battery Energy Storage Systems: A Case Study of The Cyprus Islanded Power System

Cascading failures pose significant frequency and voltage stability challenges in Renewable Energy Source (RES)-rich grids, especially when the system unintentionally splits, leading to widespread blackouts. This paper presents a novel method for identifying strategic buses for the deployment of decentralized battery energy storage systems (BESS), enabling islanded-mode operation to support split areas and thereby enhance grid resilience against cascading failures. The method performs risk-aware, budget-constrained optimal BESS allocation that accounts for load/RES uncertainty and worst credible contingencies, while integrating dynamic cascading-failure modelling and analysis to evaluate system-wide performance under BESS-provided grid support. It explicitly considers cascade-triggering mechanisms in frequency, voltage, and line loading—such as RoCoF, frequency nadir, voltage bounds, and thermal limits—together with a budget limit, by incorporating them into the optimization constraints. This enables optimal BESS allocation to mitigate cascading risks and enhance decentralized resilience by providing grid services such as voltage and frequency regulation, while reducing reliance on conventional load shedding, particularly during islanded operation through a virtual synchronous machine (VSM) control scheme. Implemented in the Cypriot power grid, the method demonstrates effectiveness in improving system resilience and reducing unsupplied load by 43.1%.