The Impacts of Increased Penetration of Distributed Generators on the Namibian Grid Stability

This paper presents the study of the impact of increased penetration of distributed generators on the Namibian grid stability. The study mainly focused on the impacts of Distributed Generators (DG's) on the grid voltage stability and overall grid power losses with wind and solar as the main DG's. Simulation was done using DigSILENT PowerFactory software. The study had been carried out under four scenarios, at 0% DG penetration (base case), 13.65% DG penetration level (considering the already existing DG's), 39.63% DG penetration level (considering the DG's that are yet to be commissioned) and the 4th simulation scenario considered mitigation measures where a shunt reactor was incorporated for reactive power compensation. In this study it had been found that an increase in DG penetration level resulted into an increase in the bus voltages beyond the upper limit of 1.05 p.u. and a decrease in grid overall active power losses from 54.38 MW to 36.83 MW. With the mitigation measures, all bus voltage had been maintained within the permissible range of 0.95 to 1.05 p.u.