Abstract

The increasing integration of large-scale photovoltaic (PV) systems into medium voltage (MV) networks presents significant challenges for maintaining voltage stability and power quality. This paper explores the operational dynamics of MV lines under high PV penetration and examines the issues associated with three voltage control methods. A specific MV line in the Koutrafas area of Cyprus, characterized by high PV penetration and minimal load, was selected as a case study. Real-time data were collected and analyzed to identify periods of significant voltage deviations. Using DIgSILENT Power Factory, simulations were conducted to evaluate the effectiveness of three voltage control methods. The findings indicate that the constant voltage control method minimizes voltage variations and offers the most reliable solution for future PV installations. However, the research highlights the need for larger inverters and advanced reactive power management capabilities to accommodate this control strategy. Recommendations are made for adopting improved voltage control mechanisms and conducting further studies to address challenges at both the distribution and transmission levels.