Determination of Winding Deformations in Power Transformers by Sweep Frequency Response Analysis and a Sample Field Study

Abstract

Power transformers are expensive pieces of electrical equipment that are used to connect transmission and distribution networks. Power transformers are inspected and tested on a regular basis throughout production, shipment, installation, and operation. There are several ways for determining the mechanical integrity of power transformers. Power transformers are monitored using these diagnostic procedures, and any breakdowns and issues are avoided. Scanning Frequency Response Analysis (SFRA) is an efficient method for determining the condition of the transformer core and windings. To evaluate the state of the transformer winding, SFRA, winding direct current resistance, and winding capacitance tests were done in this study. In the case study, a comprehensive case analysis was done on the SFRA test findings for a 50/62.5 MVA power transformer, and the results were analyzed. The results reveal that the SFRA test finds structural winding problems in transformers with high accuracy.

Keywords

• Power transformers
• Scanning frequency response analysis
• Transformer windings
• Sweep frequency response analysis

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