Source: Barrington Consultants Inc.
FRAMIT (Frequency Response Analysis Measurement and Investigation Tool) is a complete, self contained instrument
(Frequency Response Analysis Measurement and Investigation Tool) is a complete, self contained instrument that performs Frequency Response Analysis (FRA) tests on power transformers. The design of this unit incorporates the accumulated knowledge from the research and application of this test technology over the past four years. It has been designed in such a way that it is extremely easy to operate. FRAMIT performs the tests, presents the information in a meaningful manner and manages the filing of tests. The FRA method of the FRAMIT injects a high frequency voltage pulse into one of the transformer windings. The input and output voltages are sampled by a digital data acquisition unit. The two recorded time domain signals (input and output voltages), are transferred to the computer which determines the frequency spectrum (it transposes the result to the frequency domain using a Fast Fourier Transform Algorithm). The frequency response of the transformer is then obtained by dividing the frequency spectrum of the output signal by the frequency spectrum of the input signal.