Modelling and analysis of 50 MWp solar PV integration into Tanzania’s transmission network: a case study of Tagamenda substation, Iringa region

While increasing the share of renewable energy in the grid, grid integration studies for the utility solar photovoltaic (PV) plants are vital, given their intermittency and the fact that Tanzania has never had one connected to the grid. This paper presents a 50 MWp grid integration study, including a technical analysis conducted using PSS®E software. The study investigates the grid behaviour during the integration of the 50 MWp solar plant, considering the most suitable technical and economic solutions. The study analysed the load flow under normal conditions, contingency analysis (N-1), short- circuit analysis, and voltage stability assessment. The results show a reduction in power losses and relief in transmission lines that were near their maximum loading. Nonetheless, the added short-circuit current resulting from the integration of the PV plant does not cause any effects to the grid, as it is within the acceptable range of operation. The voltage stability assessment shows the grid is sufficiently robust to accommodate the 50 MWp solar plant. The study demonstrates that interconnecting the 50 MWp PV plant at the Tagamenda substation will not cause grid instability.