Frequency response analysis (FRA or SFRA) is utilized to test the mechanical integrity of transformer cores, windings, and press frames, in power transformers.
Comparing the measurements taken at various phases or on multiple identical transformers, as well as comparing measurements with the former response of the same transformer, provide indications of any mechanical or electrical changes.
The Doble M5400 Sweep Frequency Response Analyzer has an output voltage of 20 Volts peak-to-peak at 50 Ohms output impedance. With input circuitry that can analyze difference, cross-relation and sub-band at frequencies from 10 Hertz to 25 MegaHertz, the Doble M5400’s bandwidth is more than sufficient in analyzing common problems in transformers.
The Doble M5400 Sweep Frequency Response Analyzer allows for deviations identification and the confirmation of internal mechanical problems, such as:
- Core movement
- Winding deformation and displacement
- Faulty core grounds
- Partial winding collapse
- Hoop buckling
- Broken or loosened clamping structures
- Shorted turns and open windings
Features and Benefits of the M5400
- A sampling rate of 100 MS/s with a dynamic range of >90 dB.
- Provides frequency-response measurement from 10 Hz to 25 MHz; the default range (20 Hz to 2 MHz) covers the most important diagnostic areas: core and magnetic properties; winding movement and deformation; and interconnections (leads and tap changers).
- Measures frequency response at logarithmically spaced intervals of 1.2% with a constant excitation level and can auto-scale each measurement, providing an overall dynamic range of 80 dB with ±1 dB accuracy, for the highest combination of dynamic range and accuracy.
- Frequency response measurements are highly repeatable; even subtle changes can be used for diagnosis.
- Rugged construction provides the accuracy of a laboratory instrument with the ability to withstand harsh field conditions and robust test leads to handle the rigors of site testing.
Related electrical test equipment available for rent from Protec: