Investigating short-circuit in power transformer winding with quasi-static finite element analysis and circuit-based model

Detecting and removing minor faults in power transformer winding is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. In this paper in order to detect the position of short-circuit in the winding, frequency response of the input impedance of a power transformer is analyzed. Common short-circuits are categorized and the results are compared, then the behavior of frequency response due to disk-disk short-circuit is investigated. To increase the accuracy of analysis, innovative approach in finite element analysis is offered. This approach termed Electromagnetic quasi-static considers both magnetic and electric characteristics of power transformer. Simulation is fulfilled by interconnecting between finite element analysis and circuit-based model for employing short-circuit.