Fault Identification for Transformer Axial Winding Displacement Using Nanosecond IFRA and SFRA Experiments

Effect of the Asymmetrical Axial Displacement of Transformer Windings on Fra Characteristics

“…According to Fig. 5, four resonance and anti-resonance frequencies are present arising from the resonance between capacitors and inductors in the detailed model as reported in [6], [17][18][19][20][21]. In the next section, experimental FRA test is carried out on a healthy transformer to validate simulation results.…”

“…The typical frequency of the supply signal varies from 10 Hz to 2 MHz. In IFRA or LVI method, the controllable pulses are used as an input signal and the output signal is measured, where the Fourier transforms of both signals are mathematically processed to construct the frequency response characteristics [19].…”

“…As a result, the FRA characteristic of a healthy condition is different from that of a faulty condition [1,6,21,22]. Although a large number of studies have been performed on the detection of the winding axial displacement using FRA method [6], [17][18][19][20][21], [23][24][25], [27,28] but having said that, they have considered only the symmetrical axial displacement of the windings and none of them have worked on the asymmetrical axial displacement of windings which is a very common case. In this paper, the effect of asymmetrical axial displacement of the winding which is a probable case in transformers was investigated on FRA characteristics using simulation and an experimental test.…”