Study On The Characteristics And Monitoring Of GIC Vibration Of Three Phase Transformer Sets

When the geomagnetically induced current(GIC) caused by magnetic storm flow through a transformer, DC bias occurs and severe vibration, noise, harmonics, reactive power fluctuation appear. Those would be threats to a transformer’s safe operation. The vibtation problem may not lead to transformer fasteners looses and result in serious accidents such as transformer damage, and will interfere with the working of vibration analysis method for monitoring the deformation of transformer winding and iron core abnormal.The higher the voltage level of electric power system and the longer the transmission line, the GIC level is higher when geomagnetic storm occurs. The single-phase group transformers have been widely adopted in ultra-high voltage grid. Compared with other types of transformer, the single-phase group transformer is more sensitive on GIC. so when the geomagnetic storm occurs, the vibration problem is especially outstanding.Study on characteristics and monitoring method of GIC vibration is the premise of the research and monitoring GIC induced noise, and is a necessary foundation of noise suppression, but also a basic research of avoiding the interference in the use of vibration analysis method in monitoring transformer faults.Firstly, this paper analyzed the change rule of the internal magnetic field of single-phase transformer group when GIC flow in using numerical method of the coupling of magnetic field and circuit combined with ANSYS finite element software. Then analyzed the characteristics of vibration caused by GIC with the transformer model established by finite element method according to the relationship between the transformer vibration and magnetic field and current, and analyzed the difference of vibration intensity at different positions.The conclusion of this study has guiding significance for vibration and noise suppression, for the use of transformer vibration method for monitoring the running state of the transformer, and can assist the monitoring of the level of GIC when a geomagnetic storm occurs.