Frequency response analysis is a foremost strength in transformer and reactor situation analysis, permitting you to "see" internal transformers barring expensive de-tanking. Since the FRA take a look at is used to discover mechanical motion or harm in a transformer, it is almost as it should be used after some tournament or situation that has the opportunity of inflicting mechanical motion or electrical injury to the transformer meeting (e.g. earthquake). Some of the regular situations the place FRA - -measurements
maybe used include:
1. Factory short-circuit testing
2. Installation or relocation
3. After a significant through-fault event
4. As part of routine diagnostic measurement protocol
5. After a transformer alarm (i.e. sudden pressure, gas detector, Buchholz)
6. After a major change in on-line diagnostic condition (i.e. a sudden increase in combustible gas, etc.)
7. After a change in electrical test conditions (i.e. a change in winding capacitance)
Frequency response analysis measurement (FRA) standard
IEC 60076-18
"…when a frequency response measurement is required either on-site or in the factory either when the test object is new or at a later stage. This standard is applicable to power transformers, reactors, phase-shifting transformers, and similar equipment.
IEEE C57.149
"Guide for the Application and Interpretation of Frequency Response Analysis for Oil-Immersed Transformers