Coordination of single-phase rooftop PVs in unbalanced three-phase residential feeders for voltage profiles improvement

Installation of single-phase rooftop photovoltaic (PV) systems in low voltage (LV) distribution networks is gaining increasing popularity in many countries including Australia. However, installation of rooftop PVs in residential feeders without controlling their ratings and locations may deteriorate the overall grid performance including power flows, losses and voltage profiles. Therefore, in recent years the utilities have adopted limitations on the maximum allowable number of PVs in LV networks. To overcome these issues, this paper proposes an intelligent and communication-based voltage profile regulating technique which is composed of three different steps. This technique relies on the availability of smart meters at the buses. The first objective of the method is to minimize volt-age rise along the feeder by reducing the voltage at secondary side of distribution transformer. This is achieved by utilizing a distribution transformer with on load tap changing capability and a master controller located at the transformer. The algorithm also considers reactive power exchange and active power curtailment by the inverters of the single-phase rooftop PVs as the main steps for voltage profile regulation, as second objectives. The effectiveness and limitations of the proposed intelligent method are also investigated in this paper by the help of MATLAB-based simulation studies