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FRAX Software
© 2011 Megger Sweden AB
4.3.7
Analyzers...
Analyzing data will only very briefly be described in this Users’s manual. Please refer to
Megger’s application documentation and relevant guides and standards e.g.
IEC 60076-18 (a draft at time of printing this User’s Manual)
IEEE PC57.149 (a draft at time of printing this User’s Manual)
CIGRE Brochure 342
Chinese standard DL/T 911-2004
In the low frequency region, the End-to-End Open measurement reflect the magnetization
impedance, deviation in this area may indicate shorted turns or core related problems. Note
however, that residual magnetism that NOT is a failure mode, also affect this region.
In the low frequency region, the End-to-End Short measurement reflect the leakage
impedance, even small deviation in this area (>0.3 dB) may indicate severe winding
deformation.
Interpretation at higher frequencies is not covered in this User’s manual but below are
Analyzers are used to help interpret data described.
Check the box to activate an analyzer. An analyzer shows up as a separate tab in the main
screen.
The DL/T 911-2004 Analyzer is based on the Electric Power Industry Standard of People’s
Republic of China, DL/T 911-2004. The analyzer calculates the relative factor Rxy from the
correlation LRxy and implementation is only possible using SFRA Magnitude in dB-scale.
The Correlation analysis uses same calculations as DL/T 911-2004 Analyzer but here you are
able to modify, if analysis is based on LRxy or Rxy, variable for calculation e.g. Magnitude in
dB or Impedance, number of frequency ranges analyzed, frequency limits and interpretation
limits. You can make these modifications by select the Correlation analysis and press the
Settings... button.
