Energy Storage Systems Based on Sodium Metal Halides Batteries

In order to evaluate the reliability and the round-trip efficiency of grid-connected Electrochemical Energy Storage Systems (E-ESSs) based on Sodium Metal Halides (SMH) technology, the integration of Dual Active Bridge (DAB) configurations on the DC side of E-EES have been investigated. In particular, at the aim of properly managing the SMH battery DC side interface with the grid-connected converters, a standard and a partial-power DAB configurations have been analysed. In fact, the non-linear characteristic of SMH battery voltage evolution and its technological constraints require a suitable control of the current and voltage evolutions during charging and discharging. Referring to a commercial SMH battery the preliminary designs of standard and partial-power DAB configurations have been developed and the simulation results of both grid connected E-ESSs have been compared in order to analyse their performances in different SMH battery conditions.