A Novel Electrical Model for Iron Doped Sodium Metal Halide Batteries

A novel electrical model, able to mimic the dynamic behaviour of iron doped Sodium Metal Halide Batteries (SMHBs), is reported in this paper. The proposed SMHB model is a development of Thévenin-based configuration. Specifically, the model is integrated such that additional components reproduce accurately the SMHB electrochemical phenomena occurring during the discharge and charge processes. The methodology used for identification of the parameters of the proposed SMHB equivalent circuit is reported and experimentally validated. In order to highlight the improvements achieved, a comparison between the experimental and the simulated results of different SMHB electrical models was performed. The proposed model showed a significant improvement in the State of Charge range of 40% to 10%, with estimation errors, with respect to the experimental results, of less than 1%. Outcomes achieved by the proposed SMHB model open new opportunities for the exploitation of this class of battery for power system applications.