Interpretation of Sweep Frequency Response Analysis (SFRA) traces for the open circuit and short circuit winding fault damages of the power transformer

• We have developed 10 kV A power transformer to carry out SFRA testing.
• Modeling of transformer for the O.C. & S.C. testing has been done.
• SFRA testing procedure has been discussed.
• Interpretation of SFRA traces for the open circuit winding fault has been done.
• Interpretation of SFRA traces for the short circuit winding fault has been done.

This paper presents how interpretation of Sweep Frequency Response Analysis (SFRA) traces can be done for the open circuit and short circuit winding faults on the 10 kV A power transformer. The power transformer of rating 10 kV A, 11,000 V/440 V, 3-phase, 50 Hz, Dyn11 has been specially developed in-house for carrying out SFRA testing by practically simulated various transformer damages on it. Authors have discussed here open circuit and short circuit winding faults damages. The HV “W” phase open fault and HV “U” and “V” short fault has been practically simulated on the transformer separately. The result of these simulated faults are presented and discussed. The motivation of this presented work is to extend the guide line approach. Since the SFRA interpretation is based on experience, such databases are thought to be of great importance when interpreting SFRA response. The evaluation of the SFRA responses against guide lines and experience have to be performed and conclusions regarding usefulness of each simulation has been drawn and at last overall conclusion has also been drawn.