Dynamic simulation of large scale solar PV integration in medium voltage distribution networks under different load patterns

Abstract

The increasing integration of large-scale solar photovoltaic (PV) systems into medium-voltage (MV) distribution networks requires a better understanding of how different load characteristics influence network performance under high renewable penetration. Although previous studies have extensively investigated the effects of different PV penetration levels, limited attention has been given to the comparative impact of varying load patterns under identical high-PV operating conditions. To address this gap, this study presents a dynamic comparative assessment of residential, commercial, and combined load patterns in a representative Malaysian MV distribution network under 0% and 100% PV penetration scenarios. A detailed radial distribution network comprising 110 buses and eight feeders was modeled using the Quasi-Dynamic Simulation module in DIgSILENT PowerFactory to evaluate voltage profiles, feeder loading, grid power demand, and network power losses. The results demonstrate that the technical benefits of PV integration strongly depend on the temporal relationship between electricity demand and solar generation. Among the investigated scenarios, the commercial load pattern achieved the greatest reduction in network power losses, decreasing from 6.26 MW to 3.18 MW (49.2%), whereas the combined and residential load patterns achieved reductions of 28.8% and 6.5%, respectively. In addition, the residential scenario reduced upstream grid power demand by approximately 34.1%, from 200.47 MWh to 132.17 MWh, during PV operation. However, high PV penetration may also introduce voltage rise under low-demand and high-generation conditions, highlighting the need for appropriate voltage regulation strategies. The findings provide practical insights for the planning and operation of future PV-integrated MV distribution networks by demonstrating that load characteristics should be explicitly considered when evaluating the technical performance of highly PV-integrated distribution systems.