Journal of the Korean Solar Energy Society ISSN:1598-6411(Print) 2508-3562(Online) 한국태양에너지학회 논문집

The high penetration level of the generated photovoltaic (PV) power generation in low voltage (LV) networks induces the issue of voltage rise, particularly at the end of the feeders. Several solutions such as grid reinforcement, transformer tap change, demand-side management, active power curtailment, and the use of reactive power control methods have been proposed to address this issue. However, the practicability of these solutions is limited owing to high costs, low efficiencies and the conflicts of interest between network operator and the owners of solar farms. This paper proposed the use of a reactive power compensator (RPC) to mitigate the dual issues of voltage rise and voltage drop. The voltage rise is caused by the distributed generation systems while the voltage drop is caused by the heavy loads at the end of the feeder of the weak LV distribution networks. The RPC was utilized to inject the lagging or leading reactive current during the voltage drop or voltage rise condition. The proposed RPC was developed as a part of the Kepco Open R&D project. The aim of this project is to investigate the techniques to mitigate the issues for the voltage rise and drop in the distribution networks, without either changing the service transformer tap or installing an additional distribution line and service transformer. The performance of the proposed RPC was verified via simulation and experiments.