Evaluation of Single-Phase PV Smart Inverter Functions in Unbalanced Residential Distribution Systems

Abstract

Rooftop single-phase PV smart inverters in residential distribution systems are becoming more common throughout the United States. As a result, utilities are experiencing increases in the numbers of operations for voltage regulators and on-load tap changers under certain operating conditions for high PV penetration levels which may lead to reduced maintenance intervals. However, PV smart inverters can be controlled under different functions or operating modes with some potentially reducing the number of operations of voltage regulators and thus, increasing maintenance intervals. To this end, three selected functions of PV smart inverters are evaluated on a case study based on a 13.8-kV modified IEEE 37-bus system controlled under conservation voltage reduction and integrated Volt/VAr using EPRI OpenDSS™ software package to demonstrate that some functions do positively assist in voltage regulation and reactive power control.