Applying VRB-ESS in the DC micro-grid for green building electricity supply: Constructive suggestions to improve the overall energy efficiency

This paper proposes comprehensive methods to improve the energy storage efficiency of the vanadium redox flow battery energy storage system (VRB-ESS) as well as the overall energy efficiency of the DC micro-grid for green building electricity supply. It includes a novel design concept of the bidirectional (charge/discharge) DC/DC converter circuits which link VRB with DC micro-grid, the principle of how to set the nominal voltage of the VRB and how to control these circuits' parallel operation, as well as several energy efficiency improvement measures for the establishment and operation of VRB-ESS.