Service-Oriented Fast Frequency Response from Flexible Loads and Energy Storage in Low-Inertia Power Systems
The increasing penetration of inverter-based renewable generation has significantly reduced system inertia, making modern power grids more vulnerable to rapid frequency deviations following disturbances. While a wide range of flexible resources-including electric vehicles (EVs), data centers, and battery energy storage systems (BESS)-have demonstrated the physical capability to provide fast frequency response (FFR), existing studies primarily focus on individual resource performance or controller-level designs. A systematic framework that translates heterogeneous FFR capabilities into deployable, system-level frequency services remains largely unexplored. This paper proposes a service-oriented coordination framework for fast frequency response from flexible loads and energy storage, bridging the gap between physical capability assessment and grid-operational utilization. The framework decomposes frequency support into multiple time-critical service layers based on response speed, power capacity, and energy sustainability, and dynamically allocates FFR responsibilities among heterogeneous resources accordingly. By explicitly accounting for response latency, saturation limits, and energy constraints, the proposed approach enables coordinated dispatch that prioritizes ultra-fast resources for initial frequency arrest while leveraging slower but energy-rich resources to sustain recovery.