Paper Contents
Abstract
This paper provides detail analysis of performance and reliability of conventional transformer protection systems of the Nigeria power system through operational data records of high-voltage transformers in 24 months in six major transmission substations in Nigeria through 47 transformers. The study uses rigorous data gathering procedures and statistical tools to evaluate the output of protection systems such as dependability, security and misoperation rates. Findings indicate that reliability is a serious issue with the overall dependability index to be 0.847 and the security index at 0.764, which is quite far lower than the international benchmark of 0.95 and 0.98 respectively. The periodical misoperation rate of 19.4 is more than two times greater than the normal standards with remarkable seasonal differences using the 24.7 and 14.1 percentages in wet and dry seasons respectively.The analysis of the technology shows a distinct performance hierarchy: 28.4 percent of the electromechanical system is misoperating, 17.8 percent is misoperating of the analog electronic system, and 8.9 percent is the misoperation of the digital microprocessor based system. The correlations between equipment age indicate that performance will decrease exponentially (r -0.847), and mean time between failures is 387 days that is far below any international standard. Reliability is greatly affected by environmental issues such as temperature extremes, humidity and being near the coastline, where the effects of humidity tend to be exponential.The economic impact evaluation determines the significant expenditure that amounts to 204.1 billion naira to cover the study period, and the fraction of national GDP is 0.73 percent. Evaluation of maintenance practices shows disastrous shortcomings such as only 43 percent of recommended maintenance intervals actually getting done, 347 days on average of time it takes to order spare parts and lack of skillful technicians. The research paper makes very practical suggestions as to how the protection system can be improved in terms of modernisation plans, better maintenance programs and adaptations in the environments needed in the advancement of power system reliability.
Copyright
Copyright © 2025 Anikeze Nnamdi Ogbonna. This is an open access article distributed under the Creative Commons Attribution License.
