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Sweep Frequency Response Analyzer for Power Transformer Winding Diagnosis
The FRAnalyzer detects defects in power transformer windings and faults in the magnetic core. After the transport of transformers to site and following through faults with high currents the frequency response test should be made to ensure that the windings were not damaged.
Unique features of FRAnalyzer
- High reliability of results due to the applied measurement method and innovative connection technique
- Extremely small size through the use of leading edge technology
- Ease of use because of creative software
- Portability resulting from battery operation
How does it work?
For high frequencies the equivalent circuit diagram of a transformer winding can be drawn as a complex network of resistors, inductors and capacitors. The frequency response of this network is unique. It is like a fingerprint. Winding deformation causes one or more of the capacitors in this network to be changed. To identify these changes, which can be quite small, the new fingerprint is compared to that taken in a healthy condition. Deviations are an indicator of:
- Coil deformation -axial & radial
- Faulty core grounds
- Partial winding collapse
- Hoop buckling
- Broken or loosened clamps
- Shorted turns & open windings
Measuring Modes
The basic functionality of FRAnalyzer supports the following measuring mode (amplitude and phase):
- Voltage transfer function Uo/Ui (f)
With the integral vector network analyzer toolkit the following additional functions can also be measured:
- Impedance Function Ui/Ii (f)
- Admittance Function Ii/Ui (f)
This feature also supports the measurement of transformer short circuit impedances. The device utilizes a frequency sweep. This allows the measurement of core faults in the lower frequency range and avoids any interference due to noise signals that can affect the results. For higher frequencies this principle is very sensitive, because the generated signal has constant amplitude over the whole frequency range. An innovative connection technique ensures reliable measurements above 1 MHz.
More Information:
If you are interested in more details please get in touch with your local distributor or the OMICRON office nearest you.