Enhancing Risk Assessment In Nigerian 330kv Transmission Grid Using Fuzzy Based Ultra Capacitor

Abstract

The reliability and stability of the Nigerian 330 kV transmission grid are frequently challenged by contingencies such as line outages, equipment failures, and sudden load variations, which often result in voltage instability and large-scale blackouts. Conventional contingency evaluation methods, including deterministic and probabilistic approaches, face limitations in addressing the nonlinear dynamics, uncertainties, and rapid decision-making requirements of modern power systems. This study proposes a fuzzy-based ultra-capacitor framework for enhancing contingency evaluation in the Nigerian 330 kV transmission network. The fuzzy logic component provides an intelligent decision-making mechanism capable of handling imprecise and uncertain system data, while the ultra-capacitor offers rapid dynamic voltage support during transient disturbances. The integration of these technologies enables faster and more accurate assessment of fault scenarios, improves voltage stability margins, and reduces recovery time following disturbances. Simulation studies conducted on a modeled Nigerian 330 kV grid using MATLAB/Simulink demonstrate that the proposed system significantly improves contingency detection accuracy, reduces voltage deviations, and enhances grid resilience compared to conventional methods. The findings suggest that adopting fuzzy-based ultra-capacitor systems can provide an adaptive and robust solution for ensuring operational security, minimizing outage risks, and supporting the stability of Nigeria’s high-voltage transmission infrastructure. The results obtained were the conventional inaccurate or missing measurement data that caused poor contingency evaluation in Nigerian 330kv transmission grid was22s. However, when Fuzzy based ultra-capacitor was injected into the system , it simultaneously  reduced to19.1s and the conventional low short circuit capacity and weak grid that caused poor contingency evaluation in Nigerian 330kv transmission grid was1.5 KA. Meanwhile when Fuzzy based ultra-capacitor was input into the system, it instantly increased it to 2 KA. Finally, with these results obtained, it meant that the percentage enhancement in contingency evaluation in Nigerian 330kv transmission grid when Fuzzy based ultra-capacitor was inculcated into the system was33%.