Leakage inductance variation based monitoring of transformer winding deformation

When subjected to short circuit, the transformer winding would suffer from considerable large electromagnetic force and then be distorted to a certain degree, in which cases leakage inductance variation can be employed to analyze and determine the situation and severity of the deformation. In this paper, the transformer leakage inductance identification model is set up on the basis of equivalent circuit equation. Least squares identification method is used to identify leakage inductance. Transverse and longitudinal comparison method are used in this paper to obtain the leakage inductance variation, and then comprehensive judgment of winding deformation is available. Moreover leakage inductance variation based transformer winding deformation monitoring system is introduced, which make it passible to apply this method to practice. In the end, practical applicability is validated by PSCAD simulation results and the data from the field.