Power Quality Analysis of Three Minigrids in Kenya

Abstract

The need for a reliable and resilient minigrid power supply has grown in recent years. Power quality and stability issues have attracted much attention from researchers, utility companies and consulting engineers. This study was designed to investigate source and load integration levels, and to examine power quality and stability performance of selected minigrids in Kenya. Both qualitative and quantitative data collection techniques were used to collect data. Questionnaires were circulated to seven selected minigrids in the counties of Wajir (Hadado, Buna and Eldas), Turkana (Eliye springs, Kalobeyei and Locheromoit) and Siaya (Ndeda Island). A power quality analyzer (Fluke 1777) was used to record data from three of seven visited sites (Hadado, Locheromoit and Ndeda Island) for seven days at each site. Results show that various load categories are integrated into minigrids with the majority of the loads falling within basic and standard loads. There is still a gap regarding multiple source integration into the existing minigrids as the majority (4 of 7) of the visited sites had only one source, solar PV or diesel genset. Only one minigrid has more than one source working. Locheromoit (0.75) recorded a very poor average power factor as compared to that of Hadado (0.87) and Ndeda Island (0.89). Voltage variations for Hadado and Ndeda deviated from recommended values of 10/(-15)% and ± 10%. Harmonic distortions and frequencies from Hadado, Locheromoit and Ndeda minigrids were found to have no significant negative impact on quality and stability performance. Finally, this study has shown that there is sufficient progress on load integration and that power quality and stability of some minigrids (Hadado) must be improved.