FREQUENCY RESPONSE ANALYSIS (FRA) MEASUREMENT
Frequency Response Analysis (FRA) is conducted to assess the mechanical integrity of the transformer which may get disturbed due to transportation shocks. FRA signatures will be taken after assembly and oil filling and compared with factory testing to ensure the healthiness of core /coil assembly during transportation. These signatures will be the benchmark for future reference. The FRA signatures should be analyzed in conjunction with Impact Recorder readings. Report of Impact recorder readings is to be obtained from manufacturer.
It is recommended to follow the standard procedure for the SFRA measurement as per the Table-7. It should be done on maximum, normal and minimum tap of the transformer.
Combination of tests for Auto Transformer
Combination of tests for Shunt Reactor
In case of Shunt Reactor, FRA to be done in following combinations:
Ø H1-H0
Ø H2-H0
Ø H3-H0