Modeling of electrochemical energy storage system for PSASP transient stability analysis

Grid-forming BESS is deemed a key component for addressing the stable operation of new energy integration into the power grid. This is due to its ability to support the construction of new power systems and improve the anti-interference ability of the system. The existing grid-forming energy storage technology is largely based on virtual synchronous control and electromagnetic transient analysis in the field of microgrids. In this context, an electrochemical energy storage model suitable for PSASP transient stability analysis is established in this paper. The model includes energy storage element, power outer loop control, current inner loop control and model interface. The power outer loop control improves the design of traditional rotor motion equation and virtual stator electrical equation. The model is created using the Power System Analysis Software Package (PSASP) based on the node current injection approach, and an actual example system is used to verify the model's feasibility. The influence of the energy storage on the transient stability and small signal stability under different control strategies is analyzed.