Transmission system reliability modeling and assessment for Nigerian electric grid

This paper presents transmission grid reliability modeling and assessment that is critical to system reinforcement and expansion. This study explored an analytical approach for application on sub-Saharan African grids, which are fraught with effective expansion planning challenges or know-how. In this study, application of delivery point and system reliability concepts was explored and demonstrated, which involved using relatively known transmission system average interruption duration index (TSAIDI), transmission system average interruption frequency index (TSAIFI) and system average restoration index (SARI). These indices utilize temporal outage duration, outage frequency, and the grid's delivery points population data, which are obtained from system records and used to model the trends and values of TSAIDI, TSAIFI, and SARI for the observed period. Using these indicators in specific algorithm, options of effective long term grid expansion strategy are deducible, such as system lines or network regions requiring reinforcement for improved reliability of service delivery. In conclusion, this study established and demonstrated an effective algorithm for reliability assessment of sub-Saharan grids based on known system oriented indices.