Simulation Analysis and Scaling Test of Transformer Turn to Turn Short-Circuit Transient Characteristics Based on Field-Circuit Cooperation

Abstract

It is a common problem that transformers have different degrees of the turn to turn short-circuit (TTS). The fault severity depends on the location and size of the short-circuit. In this paper, the position of TTS is controlled in the middle of the transformer winding. And then, one transformer with 5%, 10% and 20% TTS on the high voltage side of the phase B was constructed. The transformer TTS faults from slight to deep are simulated, and the effect of different degrees of TTS on the transformer winding is analyzed. First, a three-phase transformer is modeled by the numerical computation method and simulated by the field-circuit coupling mode. The distribution of parameters such as the short-circuit current, the spatial magnetic leakage and the radial electric force under the TTS different degrees are studied. Second, combined with the winding losses, the “electric-magnetic-thermal-structural” multi-physical field coupling simulation is established. Based on this, the transient analysis of the winding temperature rise, the thermal stress and the deformation were carried out, then the TTS capacity of the transformer is estimated according to the transformer structure and the material tolerance value. Finally, the paper compares the winding temperature distribution changes between the simulation and test by designing the winding temperature rise test. Base on the above studies, the reliability of the model established in this paper and the accuracy of the transformer TTS bearing capacity from the test are verified. These provide some engineering reference significance for the subsequent transformer fault maintenance. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.