Prof. Javad Sadeh
Ferdowsi University of Mashhad
sadeh@um.ac.ir
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Title: Frequency Response Analysis (FRA) as a tools for transformer and electrical machine fault diagnosis

 

Frequency response analysis (FRA) is a well-known and accurate fault detection technique for transformers. It is possible to use this method for electrical machines’ condition monitoring due to the structural similarity between transformers and machines. In this presentation, the application of FRA for transformer and electrical machine fault diagnosis is discussed.

The sudden outage of a transformer due to a fault can cause irreparable damage to the electricity industry. Hence, by conducting momentarily inspections of the transformer’s condition, faults can be promptly detected, and the transformer can be disconnected from the power grid to prevent subsequent failures in this equipment. Detecting faults at an early stage can also result in reduced repair costs. One of the promising technique for fault detection is Frequency Response Analysis (FRA), which compares the transformer’s response in healthy and faulty conditions for understanding the occurrence of transformer faults.


As a first part of this presentation, a comprehensive and accurate modeling approach for the behavior of the transformer at different frequencies is presented, followed by an exposition of the requirements for implementing this method in order to find the fault type, severity, and location. Additionally, various methods for analyzing the results of frequency response are introduced and discussed. In this regard, attempts have been made to introduce advanced complementary methods to address the weaknesses and limitations of the frequency response method. Electrical machines are undeniably one of the most important parts of the power system. Generators supply a large portion of the electrical energy demand, and on the consumption side, electrical motors have indisputable roles primarily in the industrial section. Hence, the precise, efficient, and continuous performance of electrical machines are necessary for having a sustainable industrial development and reliable power system. Additionally, the high economic value of these devices adds to their importance. Hence, it is crucial to monitor their condition continuously and detect their faults and failures in the incipient stages.

On the one hand, the FRA fault diagnosis technique has a significant performance in transformers. On the other hand, it is always crucial to develop more precise condition monitoring methods for electrical machines, and they are very close in structure to the transformers. Hence, FRA is also used as a fault detection method for electrical machines, and it is in its first steps of development.

As a second part of this presentation, the similarities and differences of applying FRA for fault diagnosis in electrical machines will be explained. The results of experimental tests are shown and discussed. And, as a final part of this presentation the recommendations and suggestions for further researches in this field are presented.



Email: sadeh@um.ac.ir
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