@article{CRSIJ26000220,
                  author = {Udeagbala Remigius Ndidika, Mgbachi C. A. C., Egbonwonu Emmanuel Livinus, Eneh Princewill, Onigbo Chika},
                  title = {Performance Evaluation of Power Transmission Network Through Risk-Based Security Assessment using Linear Approximation Method},
                  journal = {Cosmo Research and Science International Journal},
                  year = {2025},
                  volume = {2},
                  number = {1},
                  pages = {43-63},
                  issn = {3108-1584},
                  url = {https://cosmorsij.com/published/CRSIJ26000220.pdf},
                  abstract = {The persistent power failure in the transmission network has jeopardized business and industrial activities in the country as a result of low power margin and low sensitivity in the network. This situation if unchecked can affect the system frequency and stability, and eventual lead to total collapse of the network. Modal analysis was employed to diagnose voltage instability. The concept of risk that considers both the probability of occurrence and the security of the contingency, sensitivity of voltage with respect to active power and reactive power, the variance of the load uncertainty was used to achieve the probability of distribution. Continuous severity function was adopted to quantify the severity because its uniformity quantifies the severity of the contingencies. The Nigerian 330kv transmission grid was used to illustrate the proposed method and the risk indices were evaluated after a contingency was simulated. The voltage magnitude of 2.783 Mvar/% is accepted as the critical threshold for this study. While mid-range values, such as 20.39 Mvar/% and 71.02 Mvar/%, suggest moderate sensitivity, often linked to inter area oscillations or weakly damped modes, and higher values, such as 72.98 to 125.68 Mvar/%, indicate stronger modal inference and control, they are less critical for initiating cascading failures. The result reveals that some northern Nigeria buses, and some buses at the transmission corridor including Damaturu (29Mvar), Jaligo (50Mvar), Jos (50Mvar), Maidugiri (30Mvar), Yola (50Mvar), Makurdi (50Mvar), Sakete (20Mvar) and Ugwuaji (35 Mvar), exhibit dominant modal participation, indicating heightened vulnerability to reactive power disturbances. The calculated risk indices reflect a quantitative measure of the system low voltage security levels. They are efficient means of quickly identifying and investigating situations that cause high risk to the network. The assessment highlights the bus or area that is most vulnerable to voltage instability, requiring immediate reinforcement, such as FACTs devices, to improve system resilience and reduce the risk of cascading outages across the network. Hence, continuous intelligent monitoring of the network through hazard detection and predicting devices are suggested.},
                  keywords = {Security-assessment, contingency, risk-based index, sensitivity, stability},
                  month = {July}
        }