The application of FRA-SCR in the diagnosis of transformer coil deformation

Failures of transformers can cause serious problems in electric power system, and the rate of transformer failures caused directly or indirectly by the winding deformation remains high, therefore, the study on detecting the transformer winding deformation is of great significance to avoid unexpected accidents and improve the reliability of the operation in electric power system. In this paper, by the use of ANSYS, a three-phase model of the transformer is established and the distributed capacitance and inductance parameters of windings under both normal and fault states caused by different kinds of deformation of the windings are calculated and summarized. A equivalent model of transformer windings(phase A) is also simulated using ATP, by adjusting the related inductance and capacitance parameters, the characteristic trans-admittance(I( )/U ( )) are investigated variations of the sweep frequency response curves of quantitatively under a sweep frequency voltage source of 100V in intermediate frequencies(0.5kHz-1MHz), and some preliminary conclusions are drawn here. This investigation has some degree of guiding significance in predicting structural faults of windings and is the basis for further experimental study.