Diagnosing power transformers faults

In this paper, faults in power transformers are categorized into two internal and external faults. The reasons for faults in the transformers are proposed and different faults diagnosis techniques in general and detailed manners are introduced and discussed. Some of these techniques are conventional and generally analytical; and some are novel based on wavelet transform and expert systems. Since numerical techniques in magnetic field analysis have been widely applied in recent years, they can be also used as precise and efficient methods for faults diagnosis of power transformers. The finite element method as a powerful and precise numerical technique is considered here which can also locate the fault position. Initial results in this topic are presented in this paper.