Coordinated voltage control of three-phase step voltage regulators and smart inverters to improve voltage profile and energy efficiency in unbalanced distribution networks

Abstract

This paper proposes a coordinated voltage control by three-phase step voltage regulators (3ϕSVRs) and photovoltaic (PV) units with smart inverters. An optimization problem is formulated to improve the voltage profile of distribution networks and reduce the active power curtailment of PVs. The tap positions of 3ϕSVRs and the active and reactive power output of PVs are coordinated by whale optimization algorithm. The effectiveness of the proposed approach is verified by case studies on the IEEE 123 node test feeder. The results show that the proposed approach achieves lower voltage unbalance while avoiding excessive PV curtailment, improving utility, consumer, and environmental benefits.

Keywords

• Distribution network
• Optimization
• Voltage unbalance
• Step voltage regulator
• Smart inverter