Smart Operation of Unbalanced Distribution Systems with PVs and Energy Storage

This paper presents a novel framework for optimal operation of Energy Storage Systems (ESSs) in coordination with Renewable Energy Resources (RERs) in a distribution system. The proposed model is a multi-period, three-phase, unbalanced Distribution Optimal Power Flow (DOPF) wherein mathematical models for solar photovoltaic (PV) generation and ESS are integrated. Two objectives are considered from the perspective of a Local Distribution Company (LDC): one objective seeks to minimize the LDC's energy procurement costs using a time-of-use rate, and the second objective minimizes total losses of the feeder. Multiple case studies are carried out to examine the operational scheduling of the ESS when placed nearby the substation and at the end of the feeder. Relevant simulation results are presented and discussed to highlight the effectiveness of the proposed method for optimal operation of distribution systems with ESS and RERs. Furthermore, the effect of increasing PV penetration on the operating schedule of the ESS is also examined.