Optimization of distributed generation based on PV systems in Rwanda electrical network

Abstract

For active power loss decrease and voltage profile improvement, the application for best-located and best-sized distributed generation remained important while planning for power system enhancement. This research aimed to determine the optimal placement and the optimal size of PV-based DGs on Rwanda electrical distribution network. First, the whole Rwanda distribution network was studied to identify the feeder with the highest power losses and that feeder was taken it as a case study. Butare feeder located on Kigoma Substation in the Southern province of Rwanda was found to have the highest power losses. Second, the Simulations were carried out on the Butare feeder distribution network, and the data from the feeder distribution network were processed with help of ETAP software to identify weak buses (WBs) i.e., buses whose voltages were beyond permissible limits. Third, the best locations for the best-sized PV-based DGs were found in the proximity of the feeder WBs. The particularity of the research relied on employing WB and WIA approaches for location and size selection criteria respectively. Forth, after connecting PV-based in the feeder distribution network, the simulated results were discussed by observing the effect of DG on Rwanda distribution network in terms of power loss decrease and voltage profile improvement. The simulated results demonstrated the effectiveness of the suggested approach gives better performance for the distribution network. The results revealed a considerable minimization of active power losses on the distribution network (i.e. from 1.112MW to 0.475MW) and improvement of the voltage profile of 17 weak buses whose voltages were below permissible limits and the voltage profile were highly improved on Rubona bus (i.e. from 0.91 to 1). Therefore, to optimize the Butare distribution network using a PV-based DG network, PV systems would be 30% PL and would be located at identified WBs.