Impact of Distributed Rooftop Solar Photovoltaics on Voltage Regulation and Stability in Radial Distribution Networks: A Load Flow Analysis

Abstract

This paper presents a comprehensive analysis of rooftop solar photovoltaic (PV) integration into electricity distribution networks, emphasizing its impact on voltage regulation and feeder performance under partial load conditions. A detailed load flow study was conducted using ETAP software to evaluate system behavior under two scenarios: 50% load without solar generation and 50% load with 50% solar power injection. The analysis reveals that distributed solar generation enhances voltage stability, particularly in mid-feeder sections, by partially compensating for voltage drops caused by cumulative load and line impedance. Upstream voltages remain high due to proximity to the distribution transformer, while downstream voltages experience significant decline, indicating limitations of solar injection at feeder extremities. Results highlight the importance of strategic placement, optimal sizing of solar units, and reactive power compensation measures, alongside advanced grid technologies such as voltage-controlled inverters, to maintain voltage within permissible limits. These findings demonstrate that distributed solar integration not only improves power quality and reduces feeder stress but also supports sustainable, resilient, and efficient operation of distribution networks under high renewable penetration scenarios.