Analysis of thevenin equivalent network of a distribution system for solar integration studies

The high target of EU renewable standard, increasing technology investment and the cost reduction are nowadays the main driving factors for the renewable generation penetration. As a reliable energy resource, solar energy from photovoltaics (PVs) is seen as one of the important renewable generations and expected to play a significant role in the future sustainable energy system. Currently one of the main issues for solar integration is the voltage regulation problem in the LV grid, as to the small X/R ratios. Hence, the voltage control techniques developed for the MV and HV networks may need to be further evaluated before applied for the LV grid. For the inverter voltage control design, it is useful to develop a realistic Thevenin equivalent model for the grid to ease the analysis. In this paper, case studies are performed based on the analysis of a realistic distribution network for the design of inverter voltage controller. Finally suggestions are proposed for the Thevenin equivalent model development.