Research Article | | Peer-Reviewed

Impact of Reactive Power Support on Voltage Stability in High PV Penetration Weak Grids: A Seasonal Analysis of the River Zone Network in Niger

Received: 4 May 2026     Accepted: 15 May 2026     Published: 23 July 2026
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Abstract

The increasing penetration of utility-scale photovoltaic (PV) systems in weak transmission grids introduces significant reactive power deficiencies that threaten voltage stability, particularly in developing countries where compensation resources are limited. This paper investigates the impact of multi-step switched capacitor bank reactive power support on voltage stability in the River Zone (RZ) network of Niger, a weak transmission grid undergoing significant PV capacity expansion. A quasi-dynamic simulation framework solves time-series alternating current (AC) power flows at hourly resolution across three representative seasonal periods (January, May, and August) under two scenarios: a baseline case without reactive compensation, and a mitigation case with dynamic hysteretic capacitor bank control. Voltage profiles (VP) and a bus-level Voltage Stability Index (VSI) serve as the primary assessment metrics. In the baseline scenario, May emerges as the most critical period, with VSI outliers descending to 0.64~p.u. and multiple buses sustaining prolonged operation below 0.80~p.u. Under the mitigation scenario, reactive compensation consistently lifts the VSI above the 0.90~p.u. stable threshold across all seasons and eliminates all collapse-risk outliers. The results demonstrate that multi-step capacitor bank support is an effective and seasonally robust voltage stabilization strategy for weak Sub-Saharan African grids with high PV penetration. The findings further highlight the need for systematic reactive power planning and dynamic compensation deployment as an integral component of renewable energy integration strategies in resource-constrained grid environments.

Published in American Journal of Energy Engineering (Volume 14, Issue 3)
DOI 10.11648/j.ajee.20261403.11
Page(s) 99-107
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2026. Published by Science Publishing Group

Keywords

Stability, Reactive Power, Photovoltaic Integration, Weak Grid, Quasi-dynamic Simulation, Niger

References
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Cite This Article
  • APA Style

    Halarou, H. A., Ladoua, I. Y., Fati, A. O., Moumouni, Y., Saidou, M. (2026). Impact of Reactive Power Support on Voltage Stability in High PV Penetration Weak Grids: A Seasonal Analysis of the River Zone Network in Niger. American Journal of Energy Engineering, 14(3), 99-107. https://doi.org/10.11648/j.ajee.20261403.11

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    ACS Style

    Halarou, H. A.; Ladoua, I. Y.; Fati, A. O.; Moumouni, Y.; Saidou, M. Impact of Reactive Power Support on Voltage Stability in High PV Penetration Weak Grids: A Seasonal Analysis of the River Zone Network in Niger. Am. J. Energy Eng. 2026, 14(3), 99-107. doi: 10.11648/j.ajee.20261403.11

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    AMA Style

    Halarou HA, Ladoua IY, Fati AO, Moumouni Y, Saidou M. Impact of Reactive Power Support on Voltage Stability in High PV Penetration Weak Grids: A Seasonal Analysis of the River Zone Network in Niger. Am J Energy Eng. 2026;14(3):99-107. doi: 10.11648/j.ajee.20261403.11

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  • @article{10.11648/j.ajee.20261403.11,
      author = {Hamza Abarchi Halarou and Ibrahim Yaou Ladoua and Amadou Oumarou Fati and Yacouba Moumouni and Madougou Saidou},
      title = {Impact of Reactive Power Support on Voltage Stability in High PV Penetration Weak Grids: A Seasonal Analysis of the River Zone Network in Niger},
      journal = {American Journal of Energy Engineering},
      volume = {14},
      number = {3},
      pages = {99-107},
      doi = {10.11648/j.ajee.20261403.11},
      url = {https://doi.org/10.11648/j.ajee.20261403.11},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajee.20261403.11},
      abstract = {The increasing penetration of utility-scale photovoltaic (PV) systems in weak transmission grids introduces significant reactive power deficiencies that threaten voltage stability, particularly in developing countries where compensation resources are limited. This paper investigates the impact of multi-step switched capacitor bank reactive power support on voltage stability in the River Zone (RZ) network of Niger, a weak transmission grid undergoing significant PV capacity expansion. A quasi-dynamic simulation framework solves time-series alternating current (AC) power flows at hourly resolution across three representative seasonal periods (January, May, and August) under two scenarios: a baseline case without reactive compensation, and a mitigation case with dynamic hysteretic capacitor bank control. Voltage profiles (VP) and a bus-level Voltage Stability Index (VSI) serve as the primary assessment metrics. In the baseline scenario, May emerges as the most critical period, with VSI outliers descending to 0.64~p.u. and multiple buses sustaining prolonged operation below 0.80~p.u. Under the mitigation scenario, reactive compensation consistently lifts the VSI above the 0.90~p.u. stable threshold across all seasons and eliminates all collapse-risk outliers. The results demonstrate that multi-step capacitor bank support is an effective and seasonally robust voltage stabilization strategy for weak Sub-Saharan African grids with high PV penetration. The findings further highlight the need for systematic reactive power planning and dynamic compensation deployment as an integral component of renewable energy integration strategies in resource-constrained grid environments.},
     year = {2026}
    }
    

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  • TY  - JOUR
    T1  - Impact of Reactive Power Support on Voltage Stability in High PV Penetration Weak Grids: A Seasonal Analysis of the River Zone Network in Niger
    AU  - Hamza Abarchi Halarou
    AU  - Ibrahim Yaou Ladoua
    AU  - Amadou Oumarou Fati
    AU  - Yacouba Moumouni
    AU  - Madougou Saidou
    Y1  - 2026/07/23
    PY  - 2026
    N1  - https://doi.org/10.11648/j.ajee.20261403.11
    DO  - 10.11648/j.ajee.20261403.11
    T2  - American Journal of Energy Engineering
    JF  - American Journal of Energy Engineering
    JO  - American Journal of Energy Engineering
    SP  - 99
    EP  - 107
    PB  - Science Publishing Group
    SN  - 2329-163X
    UR  - https://doi.org/10.11648/j.ajee.20261403.11
    AB  - The increasing penetration of utility-scale photovoltaic (PV) systems in weak transmission grids introduces significant reactive power deficiencies that threaten voltage stability, particularly in developing countries where compensation resources are limited. This paper investigates the impact of multi-step switched capacitor bank reactive power support on voltage stability in the River Zone (RZ) network of Niger, a weak transmission grid undergoing significant PV capacity expansion. A quasi-dynamic simulation framework solves time-series alternating current (AC) power flows at hourly resolution across three representative seasonal periods (January, May, and August) under two scenarios: a baseline case without reactive compensation, and a mitigation case with dynamic hysteretic capacitor bank control. Voltage profiles (VP) and a bus-level Voltage Stability Index (VSI) serve as the primary assessment metrics. In the baseline scenario, May emerges as the most critical period, with VSI outliers descending to 0.64~p.u. and multiple buses sustaining prolonged operation below 0.80~p.u. Under the mitigation scenario, reactive compensation consistently lifts the VSI above the 0.90~p.u. stable threshold across all seasons and eliminates all collapse-risk outliers. The results demonstrate that multi-step capacitor bank support is an effective and seasonally robust voltage stabilization strategy for weak Sub-Saharan African grids with high PV penetration. The findings further highlight the need for systematic reactive power planning and dynamic compensation deployment as an integral component of renewable energy integration strategies in resource-constrained grid environments.
    VL  - 14
    IS  - 3
    ER  - 

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