The application of sweep frequency impedance on the diagnosis of short circuit faults within transformer winding

摘要

As a central device of a power system, the safe running of a power transformer is considered to be significance. Through the statistics of onsite faults, the amount of the transformer winding deformation caused by short-circuit faults within transformer winding is maximum, therefore the detecting on the short circuit faults is important to improve the reliability of power transformers in service. In this paper, a data acquisition system has been developed based on a signal source and a power amplifier, and the short circuit faults are simulated by using a three-phase transformer in lab, as well as the sweep frequency impedance (SFI) curves are extracted and analyzed to find out the inner relevancy. The result indicates that the resonance frequencies and their amplitudes of the sweep frequency response curves vary as the degree and type of short circuit faults differ, and by analyzing the relationship between each curve, some preliminary conclusions can be drawn here. This investigation has some degree of guiding significance in predicting structural faults of windings in the transformers and is the basis for further experimental studies.