Evaluating The Aggregated Frequency Regulation Capability of Energy Storage Clusters

With the integration of a large number of wind and solar new energy power generation into the power grid, the system faces frequency security issues. Energy storage stations (ESS) can effectively maintain frequency stability due to their ability to quickly adjust power. Due to the differences in the state of each ESS and the topology of the power grid, it is difficult to evaluate the frequency support capability of the energy storage cluster (ESC) in real-time. This paper proposes a real-time evaluation model for the aggregated frequency support capability of ESC. The evaluation indicators for inertia support and primary frequency regulation (PFR) capability is proposed respectively. Considering the aggregation effect of ESC, the evaluation of frequency support ability for ESC is transformed into an optimization problem. This article establishes evaluation models for the inertia support capability and primary frequency regulation capability of ESC, respectively. In the evaluation model, we establish frequency response models for ESS based on virtual inertia and droop control, considering the differences in the states of each ESS and network security constraints. The case study shows that the model can evaluate the frequency support capability of energy storage clusters based on their real-time status. When considering network constraints, the supporting capacity of ESC exhibits spatial distribution characteristics.