Research on Oil Chamber Flow in On-load Tap-changer Switching Process with CFD

The on-load tap-changer is one of the key components of the converter transformer. The arc generated by the oil-extinguishing on-load tap-changer switching process will cause the insulating oil in the diverter switch oil chamber to be thermally expanded and surging. In order to accurately reflect the flow field shape inside the diverter switch oil chamber, the three-dimensional flow simulation software Fluent is used to add the energy generated by the arcing process in the form of User Defined Function. The Realizable k-epsilon model is selected for a model double. Numerical simulation of the flow of the on-load tap-changer oil chamber. By comparing and analysing the similarities and differences of oil pressure and oil flow in oil chamber under different capacity transition resistance conditions, it can be seen that when the transition resistance is too small, the pressure and flow of the oil chamber will change greatly. The simulation results can provide reference for the selection of the on-load tap-changer transition resistance and the configuration of the oil flow relay.