Techno-economic impacts of Volt-VAR control on the high penetration of solar PV interconnection

This paper investigates the operation and control of smart inverters (SI) for solar and solar-plus-storage systems with an emphasis on Volt-VAR Control (VVC) at solar interconnections. The paper provides techno-economic recommendations for both normal-size and oversized solar inverters equipped with VVC. The objective is to minimize the voltage violations, and active power curtailment by providing reactive power support to the grid while the IEEE 1547-2018 standards are satisfied. Moreover, a collaborative VVC is tested where a battery storage system is paired with the solar facility which is becoming a popular configuration to enhance energy resilience in communities. An unbalanced distribution network is modeled based on a modified IEEE 13-bus system to which three 700 kW solar PV plants are connected through smart inverters. Solar data from the University of Louisiana’s 1.1 MW solar farm is used and grouped into 28 clusters. Those clusters represent a 2-year period with 15-min granularity. Typhoon HIL 402 real-time simulator is utilized for modeling and verifying the proposed approach. A control prototype is also developed on dSPACE MicroLabBox to further investigate the interaction between the controller and the rest of the system in a more realistic testing environment.