Sweep frequency response is a major advance in transformer condition analysis, allowing visualization of the inside of a transformer’s tank without costly de-tanking.  This is done by performing a simple measurement looking at how well a transformer winding transmits a low voltage signal that varies in frequency. Just how well a transformer does this is related to its impedance, the capacitive and inductive elements that are intimately related to the physical construction of the transformer. Changes in frequency response as measured by SFRA techniques may indicate a physical change that has occurred inside the transformer, and thus a change to the transformer’s impedance.  The cause of the impedance change then needs to be identified and investigated.

Learning Objectives:

• Describe impedance and how it is affected by frequency.
• Explain the process of a swept frequency response.
• Review and interpret SFRA test results.
• Define typical test connection.

Prerequisites:

Participants should have basic knowledge of basic electricity and AC reactive components.