Development of a Power Electronics Interface between an Energy Storage System and the Power Grid

Concerns related to reducing the environmental footprint triggered a great search for new sources, particularly renewable energy sources (RES). However, the high intermittency of the RES combined with the decentralized generation (DG) is causing a set of new challenges for power grids (PG). One possible solution to deal with this problem is the iteration of energy storage systems (ESS), namely battery energy storage systems (BESS), to store the excess energy during off peak hours, to be used during on peak hours. This paper proposes the power electronics converters to interface a BESS with the PG, based on a two-leg interleaved dc-dc bidirectional converter and a three-level dc-ac neutral point clamped inverter (NPC). Simulation results shows that with proposed topology it is possible to maintain a current with low ripple from the BESS side as well as with sinusoidal currents with very low total harmonic distortion (THD) from the PG side.