Determination of winding destroy limit area for a power series of amorphous core transformers

Abstract

The amorphous steel core transformer features a unique structure with a rectangular winding, resulting in an uneven distribution of electromagnetic force compared to the circular winding of silicon core transformers. Consequently, evaluating the added value of electromagnetic waves and identifying the destructive areas of winding are crucial. In this paper, the combination of Matlab and the finite element technique is developed to calculate the magnetic field, short-circuit current, and electromagnetic force for 3-phase amorphous transformers (22/0.4 kV) during short-circuit faults. The findings establish a relationship between the electromagnetic force value during a short circuit and the winding radius, as well as identify the areas where the winding damage is confined based on the transformer power sequence. These research results assist designers, manufacturers, and transformer operators in determining the appropriate harmful conditions of short-circuit electromagnetic force for the windings.