Quantifying Power Quality in Stand-alone Minigrids Using Fuzzy Power Quality Indices: a Case of Illaut Minigrid in Sub-saharan Africa

Publication Type

Journal Article

Name of Author

• D. E D. E. Nkolokosa, Department of Physics, University of Nairobi, Nairobi (Kenya)Follow
• Sebastian Waita, Department of Electrical and Information Engineering, University of Nairobi, Nairobi (Kenya)
• Mutugi Kiruki, Department of Electrical and Information Engineering, University of Nairobi, Nairobi (Kenya)
• Walbermark Marque dos Santos, Department of Electrical Engineering, Federal University of Espirito Santo, Vitoria (Brazil)

Publication Date (Issue Year)

2026

Journal Name

International Solar Energy Society

Abstract

Recently the concept of power quality in stand-alone minigrids is gaining wide recognition. The inherent uncertainties and dynamic operating conditions of the decentralised energy systems have promoted calls for increased research activities in power quality assessment and improvements. This study proposes an innovative approach for quantifying power quality in stand-alone minigrids. The existing conventional power quality indices have limited operational capacity; hence, they require improvement in terms of accuracy, reliability and versatility. The proposed methodology incorporates a hierarchical evaluation index comprising harmonic distortion, frequency fluctuation, voltage variation, dips and interruptions. Results indicate that interruptions got the lowest power index (0), indicating a critical power quality concern. The recorded total fuzzy power quality index for the entire system was below 20%, demonstrating very poor power quality.

Keywords

minigrids, power quality index, voltage variation, fuzzy, power reliability

Rsif Scholar Name

Duncan Nkolokosa

Rsif Scholar Nationality

Malawi

Cohort

Cohort 3

Thematic Area

Energy including Renewables

Africa Host University (AHU)

University of Nairobi (UoN), Kenya

Recommended Citation

D. E. Nkolokosa, D., Waita, S., Kiruki, M., & dos Santos, W. M. (2026). Quantifying Power Quality in Stand-alone Minigrids Using Fuzzy Power Quality Indices: a Case of Illaut Minigrid in Sub-saharan Africa. International Solar Energy Society https://doi.org/10.18086/swc.2025.07.12