Sweep frequency response analysis (often referred to as SFRA or FRA) is a powerful and sensitive method for testing the mechanical integrity of transformer cores, windings, and press frames in power transformers.
Recommend testing the frequency response after transport of transformers or after faults at high currents have occurred.
Benefits:
Non-Destructive: SFRA is a non-intrusive test, meaning it does not harm the transformer or disrupt its operation.
Preventive Maintenance: Regular SFRA testing can detect issues before they lead to failures, allowing for planned maintenance and minimizing unexpected downtime.
Complementary: SFRA complements other diagnostic tests like Dissolved Gas Analysis (DGA), electrical tests, and visual inspections, providing a comprehensive assessment of transformer health.
Limitations:
Interpretation of results requires skilled personnel and understanding of transformer construction and potential failure modes.
Environmental factors (temperature, humidity) and test setup variations can influence the measurements, necessitating careful control and normalization procedures.
SFRA may not detect all types of faults, particularly those not affecting the overall winding configuration.
In summary, Sweep Frequency Response Analysis is a powerful diagnostic tool for assessing power transformer health by analyzing the transformer's response to a range of frequencies. Its ability to detect winding issues early on makes it a valuable part of transformer maintenance programs.