Modelling of NAS energy storage system for power system applications

At present new materials and development approaches in battery systems are aimed at replacing Lead Acid batteries, not only their common market-available forms but also, in some cases, as devices for large energy storage systems due to their better overall performance. Among these new battery types, sodium-sulphur batteries are a new practical and economical competitive solution to store large amounts of energy. They have many advantages such us the use of non-polluting components and longer life. Using power electronics, these new batteries can be used for peak saving (PS) or power quality (PQ) purposes. In either case, it is necessary to study their dynamic behaviour through a representative model. This work firstly describes the main features of sodium batteries. Then, it presents a new model developed in MATLAB/Simulink and implemented in a testing power system. Analysis and conclusions are included in the final sections.