Operational DER Scheduling Tool for Unbalanced Distribution Systems Considering Watt-VAr Controllers of PV Smart Inverters

Increased penetration of Distributed Energy Resources (DERs) in distribution feeders may have reduced dependency to meet demand with power from substation, but has also lead to a rapid rise in several power quality issues. An effective DER scheduling model is required to combat issues related to system requirements and power quality. This paper proposes a DER scheduling tool using a robust AC optimal power flow (ACOPF) model for an unbalanced distribution system with Watt-VAr curves modeled. The Watt-VAr curves are mathematically modeled using a mixed-integer formulation based on the IEEE 1547–2018 standard. This ensures accurate real-time reactive power dispatch to support local and system-wide over-voltage issues. The proposed tool is tested on a snapshot of a distribution feeder in Arizona. The proposed tool is also compared with the Volt-VAr control mode, generally deployed among DERs. The potential of the tool for feeder-wide deployment is illustrated by the results.