Condition Monitoring of Power Transformer by Using SFRA Test

Transformers are the most critical part of electrical transmission and distribution network, also when it is come to quality and continuity requirements on delivery of electrical energy. Power outages cause loss of income for power consumers and the power industry itself, as well as loss of consumer confidence in the power provider. Transfer function measurements have been used as a diagnostic tool to detect mechanical failures in power transformers. Geometrical changes in the transformer windings and core due to mechanical stress can be reflected as a change in the RLC parameters of the equivalent circuit of the power transformer. Such changes can be detected through the change in the transfer function. [1] This paper discusses the measurement principle of sweep frequency response analysis (SFRA) on power transformer and result interpretation, which is complimented with case studies. Frequency Response Analysis (FRA) is the only reliable technique often called as tool for determining mechanical faults in transformer winding. There are main techniques available for the electrical fault detection. [2].