Impact of Photovoltaic Penetration on Voltage Stability of Radial Distribution Networks using Monte Carlo Simulation

Abstract

In countries like Nepal, solar PV and wind are seen as the most efficient forms of distributed generation. Adding PV as a renewable energy source to the power distribution system has helped improve voltage levels and cut down energy losses. However, there is a limit to how much PV can be added, as it can cause various problems in the power system including increased line losses and voltage stability issues. In Nepal, most consumers are connected through radial distribution networks that can be very long, sometimes hundreds of kilometers, leading to bigger voltage drops and more line losses. Adding small amounts of PV doesn’t cause any issues, but when the amount goes beyond 30-40%, some negative effects start showing up. So, there’s a balance between improving voltage and reducing losses, and the main aim of this paper is to calculate the best level of PV penetration. In this research paper, the Voltage Stability Index (VSI) is utilized to locate the buses that have the lowest VSI and are at risk of collapsing under heavy loads. The PVDG is then placed at the bus which has lowest VSI, and the PV penetration level is increased from 0 to 80% in the steps of 20 to see the results. These results are then compared and analyzed to find the optimum solution. The study was carried out on the IEEE-33 radial distribution system and the East feeder of Rajbiraj DC, Saptari. The results show that with the optimal amount of PV integration, the voltage profile and VSI of the system improve significantly.