ONLINE IDENTIFICATION OF MAGNETIZING INRUSH AND INTERNAL FAULTS IN 3-PHASE TRANSFORMERS

This paper presents a microprocessor-based system for on-line identification of magnetising inrush and internal fault conditions in three-phase transformers. The system uses a digital algorithm which is based on a transformer model and can be used irrespective of the fact whether or not it is possible to measure winding currents. The proposed system is suitable for monitoring the health of transformers and for controlling the operation of differential relays. The system can also serve as a diagnostic tool for detecting internal faults in transformers.