Development of a protection and control scheme for the interconnection of two rural isolated PV mini grids in Uganda

Abstract

Extension of the main grid to remote areas is economically not feasible. To electrify remote areas, one of the best choices is to install Renewable Energy Sources (RES) as distributed generation (DG) and thus form a mini-grid (MG) in islanded (Stand‐alone) mode. In islanded mode, the MG has no support from the national grid. Thus, the overloading of islanded DC MG can collapse DC bus voltage and cause fluctuation in the load. Therefore, interconnecting mini grids offers an appealing solution. Whenever a mini grid faces deficiency, it can get power from the interconnected neighbor. Many methods for power sharing also aim at minimizing circulating currents which cannot be avoided when every MG feeds their load locally. Therefore, the proper power balancing among generation, loads, and in between MG cluster is challenging in islanded topology. In this project, the interconnection of Kyamugarura and Kanyegaramire mini grids were modelled and simulated in DigSILENT simulation software for the protection aspect and in MATLAB/Simulink environment for the control aspect.