Integration of solar power plants in medium voltage grids and its impact on load flow and grid stability

The rapid deployment of photovoltaic solar power plants (PVSPs) has introduced a range of technical challenGES to existing distribution networks. This thesis presents a comprehensive analysis of the impact of integrating a 16 MW grid-connected solar power plant with two static loads of 1.6 MW and 10 MW, respectively. Utilizing the DIgSILENT PowerFactory simulation environment, the study evaluates critical performance indicators including voltage profile, active and reactive power flow, short-circuit capacity, and power quality parameters. Unlike conventional studies which focus predominantly on the generation side, this work incorporates both generation and load dynamics, thereby providing a holistic assessment of energy balance and its effect on grid behavior. Key issues such as voltage deviations, reverse power flow, low short-circuit capacity, and harmonic distortion are systematically investigated under varying load conditions. The scenario-based analysis demonstrates that the simultaneous operation of high-capacity loads and solar generation units within the same distribution feeder or transformer substation may introduce significant grid stability concerns. Moreover, the voltage support capability of the PV plant was found to vary depending on the size and location of the connected load. The findings underscore the necessity of conducting detailed technical assessments prior to integrating solar generation into conventional grids, and offer practical engineering recommendations for distribution network planning. The proposed modeling framework contributes to the literature by addressing a critical gap through a scenario-driven, dual-sided (generation and load) integration perspective.