Variability of the Voltage Stability Margin under Load Uncertainty in the IEEE 14-Bus System
DOI:
https://doi.org/10.47187/perspectivas.8.2.264Keywords:
Uncertainty Analysis, Voltage Stability, Power Flow, Monte Carlo Method, Electric Power SystemsAbstract
This article analyzes the variability of the estimated voltage stability margin under load uncertainty in the IEEE 14-bus system. For this purpose, Monte Carlo scenarios were generated using random factors applied to active and reactive power demands, and power flows were solved using the Newton-Raphson method. In each scenario, λmax was estimated through feasibility assessment and bisection refinement within a defined interval; discrete P-V curves were also generated to identify the critical bus and analyze the evolution of the minimum voltage at PQ buses. The results show that load uncertainty produces noticeable variations in the estimated margin, although a significant portion of the scenarios reaches the upper limit of the exploration interval. Therefore, these cases are interpreted as censored scenarios and not as exact collapse points. The relationship between total active load and λmax showed an inverse trend, indicating a reduction in the margin associated with higher demand levels. In addition, criticality was mainly concentrated at buses 5 and 14, while the representative P-V curves made it possible to link the statistical dispersion with the electrical response of the system. The proposed approach enables the voltage stability margin to be characterized from a probabilistic and reproducible perspective.
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