Transformer Models for Detection of Incipient Internal Winding Faults

Abstract: A method of modeling internal turn-to-earth and turn-to-turn faults in distribution transformer is discussed in this paper. The models are entirely compatible with the Alternative Transients Program(ATP). The simulation of the faults is based on known leakage factors between the various coils of the transformer. These leakage factors are evaluated by using a simple method implemented in this paper. A fault between any turn and earth and between any two turns on either winding of a single-phase transformer can be simulated using this method. In this paper, the terminal behavior of a test transformer is studied through the simulation of a simple system in ATP. When faults are introduced at various locations in the transformer primary and secondary windings, the terminal voltages and currents behaved as expected