Study on the Characteristics of Low-Frequency Vibration of the Core of Single Phase Transformer Set Caused by GIC

The study on characteristics of transformer vibration caused by GIC is the foundation of studies on transformer noise caused by GIC, location selection of monitoring vibration and noise. In this study, the characteristics of low-frequency vibration of the core of single phase transformer sets caused by GIC have been analyzed through building mathematical models and experimental analysis. The results show that when DC bias occurs the vibration signals contain 50 Hz and 150 Hz vibration. With the degree of DC bias the 50 Hz vibration grows by linear increase and 150 Hz vibration grows by square increase. Affected by GIC, the 50 Hz and 150 Hz vibration waveform’s phase changes with alternate 0 andπ. The characteristics of 50 Hz and 150 Hz vibration discriminate between core vibration caused by GIC and HVDC grounding currents. This study has significance for vibration monitoring of transformer faults, and can assist in determining the level of GIC.