Research Article
Impact of Reactive Power Support on Voltage Stability in High PV Penetration Weak Grids: A Seasonal Analysis of the River Zone Network in Niger
Issue:
Volume 14, Issue 3, September 2026
Pages:
99-107
Received:
4 May 2026
Accepted:
15 May 2026
Published:
23 July 2026
DOI:
10.11648/j.ajee.20261403.11
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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.
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 su...
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Research Article
Multicomponent Iridium-Based Alloy Catalysts for Enhanced Alkaline Hydrogen Oxidation Reaction
Yanfu Tong,
Zhiyuan Liu,
Xuejin Li,
Wei Xing*
Issue:
Volume 14, Issue 3, September 2026
Pages:
108-116
Received:
25 May 2026
Accepted:
25 June 2026
Published:
6 August 2026
DOI:
10.11648/j.ajee.20261403.12
Downloads:
Views:
Abstract: The sluggish kinetics of the hydrogen oxidation reaction (HOR) in alkaline media, primarily arising from the linear scaling relationship between H* and OH* adsorption energies on catalyst surfaces, remains a critical bottleneck for anion-exchange membrane fuel cells (AEMFCs). In this study, we propose a multifaceted approach to overcoming the current limitations of scaling by synthesising Ir-based ternary alloys with diverse oxophilic metals, including Mo, Ru, and Nb. The RuIrMo@MHCS catalyst, featuring a face-centred cubic single-phase solid solution with uniformly dispersed nanoparticles on hollow carbon spheres, exhibits a kinetic current density of 18.04 mA cm–2 at 50 mV overpotential and an exchange current density of 6.79 mA cm–2. This is a significant improvement over the performance of commercial Pt/C, with factors of 6.14 and 5.66, respectively. Additionally, the catalyst demonstrates excellent long-term stability. X-ray photoelectron spectroscopy reveals electron transfer from Ir to Ru upon Ru doping. Density functional theory calculations demonstrate that Ru incorporation downshifts the d-band centre of Ir, thereby moderately weakening H* adsorption (ΔGH* = –0.38 eV) while enhancing OH* adsorption on Mo sites. This adaptable calibration of intermediate adsorption energies circumvents the linear scaling constraint and substantially promotes alkaline HOR kinetics. The findings of this study corroborate the hypothesis that multicomponent alloying is an effective strategy for synergistic optimisation of H* and OH* binding, thus providing a rational design pathway for high-performance alkaline HOR catalysts.
Abstract: The sluggish kinetics of the hydrogen oxidation reaction (HOR) in alkaline media, primarily arising from the linear scaling relationship between H* and OH* adsorption energies on catalyst surfaces, remains a critical bottleneck for anion-exchange membrane fuel cells (AEMFCs). In this study, we propose a multifaceted approach to overcoming the curre...
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,
Ibrahim Yaou Ladoua
