Photovoltaic Hosting Capacity Sensitivity to Active Distribution Network Management

Abstract

The increasing integration of rooftop photovoltaic (PV) systems in low voltage (LV) distribution systems may result in technical problems such as over-voltage. Thus, utilities have been employing different active distribution network management schemes to enhance rooftop photovoltaic hosting capacity (PVHC) by mitigating the technical issues. As there are different control schemes to resolve the over-voltage issue and increase PVHC, it is necessary to develop a comprehensive method to compare their effectiveness. The aim of this paper is to investigate the effects of autonomous voltage control strategies on the PVHC in LV distribution feeders. The investigated operation strategies are based on the active and reactive power control capabilities of PV systems as well as the on-load tap changer of transformers. We propose an optimization-based framework to determine the PVHC considering the voltage control capabilities. We do this by utilizing the linear mathematical model of the PVHC, in which the voltage control strategies are modeled as equality and inequality constraints. The proposed methodology is examined on IEEE 123-bus test system as well as 128 LV UK feeders to identify the potential of autonomous voltage control strategies in increasing the PVHC. Finally, the sensitivity of the obtained results to the R/X ratio of the feeders and size of PV systems is assessed.