Evaluation for Grid-Forming Capability of Battery Energy Storage Systems

The large-scale integration of renewable energy into power systems has introduced new challenges to maintaining system safety and stability, requiring advanced inverters and rapidly controllable resources to support the dynamic security of the grid. Grid-forming battery energy storage system (GFM-BESS) can emulate the external characteristics of synchronous generators to support the grid, making it a crucial component for providing support in future low-inertia power system. There are rare reports on the evaluation of the grid-forming (GFM) capabilities of GFM-BESS. To address this, this paper proposes an evaluation framework for evaluating the GFM capabilities of GFM-BESS. Firstly, the GFM control technology and the typical operating conditions are described. Then, the corresponding evaluation indicators based on frequency support, voltage support, transition between isolated and grid-connected modes, and black start service scenarios are proposed, which constitute a complete evaluation framework. Finally, the evaluation framework is validated through simulation tests and result analysis in Matlab/Simulink/PLECS. The results demonstrate that the proposed evaluation framework effectively reflects the GFM performance of GFM-BESS.