The Transformer Winding Deformation Tester under Wuhan UHV can help many power workers conduct various power tests more conveniently.
The frequency response method and low-voltage pulse method used in transformer winding deformation testing are both non-destructive testing methods based on electrical measurements. The following is an explanation of the two methods:
FRA (Frequency Response Analysis)
1.High Precision
Highly sensitive to minor deformations (e.g., slight displacement between turns, local loosening of windings), enabling early detection of latent defects.
Detects subtle changes via high-frequency resonance peaks/valleys, offering superior resolution.
2.Detects Minor Deformations
Effective for identifying distributed deformations (e.g., overall winding tilt, looseness) or localized minor damage (without significant impedance changes).
Limitation: Weak localization – only identifies approximate areas of abnormality (e.g., "high-frequency anomalies indicate issues near the winding end").
3.Requires Expert Analysis
Relies heavily on comparison with historical baseline curves. Interpreting curve deviations demands expertise (e.g., peak shifts may indicate shorts, displacement, or loose leads).
Vulnerable to environmental interference (e.g., grounding issues, electromagnetic noise), necessitating strict operational protocols.
LVI (Low Voltage Impulse Method)
1.Simple Operation
Rapid testing: Single pulse injection (nanosecond-level) with direct time-domain waveform capture, no frequency sweeping needed.
2.Quick Identification of Severe Deformations
Highly sensitive to significant impedance mutations (e.g., inter-turn shorts, lead breaks, major radial deformation):
Short circuit → Negative reflection wave (impedance decrease).
Open circuit/break → Positive reflection wave (impedance increase).
Key strength: Precise localization – calculates electrical distance to fault points (±1% accuracy) via reflection wave timing.
3.Strong Anti-Interference Capability
Minimal impact from power-frequency electromagnetic interference, suitable for complex field environments.
No frequency-sweeping process ensures high data stability.