Probabilistic Analysis of the Reliability Performance for Power Transformers in Egypt

Abstract

From reliability, maintainability, and availability (RAM) points of view, the performance of power transformers has a significant impacts on the performance of the entire power network. Their performance has also a significant impacts on the power interruptions at various voltage levels and the consequent customer interruption costs. This paper will discuss the estimated remaining lifetime of power transformers in the voltages subpopulations: 500kV, 220 kV, 132 kV, 66kV and 33 kV of the Egyptian grid as time between failures (TBFs) will be determined and then determine the best fit probability distribution using MATLAB program for repair time, customer interruption costs (CIC) and TBFs, this is performed in order to estimate remaining lifetime of the transformers, from which the best fit probability distribution will be used in this case study which is Weibull distribution. Finally availability of the transformers per different voltage populations is calculated and determined. Different subassemblies (failures) are also undergo the same process of determining TBFs and estimating remaining lifetime. The results will be helpful in the manufacturing process of the transformers and enhancing the maintenance schedule.

Keywords

• “transformers”, “weibull distribution”, “remaining lifetime”, “availability”