Proposed Small Signal Dynamic Model for a Grid-Connected Battery Storage System

This paper presents a new small-signal dynamic model for a grid-connected battery storage system (BES). This model, which is based on the equivalent circuit of the battery bank and dc/ac converter, is a helpful tool for the stability analysis of the power system. In this model, the On-Off status of converter switches is controlled by deviation of the frequency of the ac grid. To determine the dynamic model of BES, first, we linearized the equation of the battery bank, dc/ac converter, and its controller around a stable operating point. Then by augmenting these equations, we determine the small signal model of the BES. To investigate the accuracy of our proposed model, we investigate a typical study system consisting of BES and a synchronous generator. We calculate the eigenvalues of this system for different penetration levels of BES. Then this system is studied with time domain simulation software. This paper shows that the results of eigenvalue analysis and time domain simulations were consistent. This similarity indicates the correctness of the presented model.