Review on voltage-violation mitigation techniques of distribution networks with distributed rooftop PV systems

The integration of the various types of distributed generators in low-voltage (LV) distribution networks becomes a great concern, especially the rooftop photovoltaic (PV) systems. The negative impacts of the rooftop PVs on the distribution feeder buses' voltage include voltage rise and voltage unbalance (VU). Such a voltage-violation condition depends mainly on the PVs ratings and the network unbalance percentage. This study presents a review for different techniques used to mitigate the voltage violation resulting from PVs integration in a typical three-phase four-wire LV distribution network case study. The voltage-violation mitigation techniques studied in this study are enhancement of the feeder, on-load tap changer, demand-side management, active power curtailment, a reactive power control, static transfer switch, energy storage systems and hybrid strategies. The LV distribution network case study was modelled based on constant power model method using MATLAB software environment. The simulation results demonstrate both voltage regulation and alleviating VU capabilities of each technique.