A New Transformer Winding RLC Model to Study the Effect of the Disk Space Variation on FRA Signature

The mechanical and electrical stability of the power and distribution transformers is essential by electricity providers and consumers. The transfer function method, specifically, Frequency Response Analysis (FRA) is quite well-known as the most accurate and reliable technique for determining the mechanical faults in transformer active part. This study presents a comprehensive method for transformer winding disk space variation (DSV) modeling using SPICE netlists. It is based on the elaborated winding RLC model, and the model data are validated with a practical work in this research work. The FRA measurements of normal and deformed scenarios are conducted and evaluated with the introduced technique. The behavior of the FRA spectra for normal and DSV scenarios is analyzed, and the model is validated and revealed a similar trend for both practical and netlists-based winding models. The proposed winding RLC model will enable researchers to study the effect of the other mechanical deformations on the frequency response curve without conducting the irreversible faults to the winding structure.