Fault analysis when a mini grid is connected to the main grid

Abstract

Increased exploitation of renewable energies for electricity generation has resulted into increase in the number of the mini grids operated either in island mode or grid connected mode. Increased generation capacity along with entrance of mini grids to the main grid causes increase in short circuit current magnitude in distribution and transmission grid substations. This project involved modelling West Nile Rural Electrification Company (WENRECO) and section of the main grid that will supply the power to that network and then connected them together.\\A three phase short circuit simulation and then fault analysis was made considering fault currents and fault MVA which showed an inrease in fault magnitudes. A study was also made on the operation and coordination of the network circuit breakers and relays. Dig Silent power factory was used in the simulation and analysis of the networks mentioned above. We propose use of SCADA for WENRECo and installation of series reactors on the line joining WENRECo to the main grid to reduce of the fault current magnitudes during fault conditions.