Assessment of Rogowski Coils for Measurement of Full Discharges in Power Transformers

Science and industry have sought to develop systems aiming avoid total failures in power transformers since these machines can be working under overloads, moisture, mechanical thermal stresses, among others. These non-conformities promote the degradation of insulation system lead transformer failure. In incipient stages faults, it is common detect Full Discharges (FDs), which are short circuits between degraded coils. Therefore, several techniques were developed perform FD diagnosis using UHF, acoustics, current sensors. this scenario, article presents a mathematical model for Rogowski coils compares two different types cores: Ferrite Teflon. For purpose, FDs induced an oil-filled transformer. The sensitivity frequency response compared. This analysis was achieved Power Spectrum Density (PSD) energy acquired signals. Additionally, Short-Time Fourier Transform (STFT) applied repetitive discharges. results indicated that core increases by 50 times band 0 1 MHz. However, Teflon showed higher 5 10