Aging assessment of power transformer using multi-parameters

As the population of transformers in service increases and their operating time extends, much attention has been focused on their availability and reliability. However, insufficient research work concentrates on how to evaluate transformer's aging condition, although huge progress has been made on the techniques of fault diagnosis and condition assessment of transformer in past decades. This paper presents the concept of Aging Index (AI), which is a practical tool that combines the results of routine inspections, and site and laboratory testing to estimate the aging condition of oil-immersed transformers. Further, frequency domain spectroscopy (FDS) as a novel non-destructive testing technique to estimate remained life expectancy is included in aging evaluation system. Moreover, a software system based on transformer's electrical and thermal parameters is developed correspondingly, by using a multi-parameters analytic approach. This system would dedicate to decision-making and replacement planning and has good application prospects.