The PFRS-25 is a power transformer frequency sweep response analyzer designed to confirm the mechanical integrity of a power transformer by measuring the frequency response per the IEEE C57.149-2012 and IEC 60076-18 standards. The included test and analysis software can be used to perform tests automatically and to graphically compare test results and provide correlation analysis per the IEEE C57.149-2012 and DL/T 911-2004 standards. The software can be used to quickly assess the mechanical and electrical integrity of the transformer under test.

The PFRS-25 can confirm the mechanical integrity of a transformer by comparing the frequency response of the transformer with the previous known results. Every transformer has a unique frequency response system which changes if the mechanical geometry of the transformer is changed. These changes can occur due to physical movement or transportation. The physical geometry can also change if the transformer experiences high fault current due to internal or external fault. The fingerprint comparison of the frequency response system can be used to detect power transformer problems such as:

  • Core movements
  • Shorted turns or open windings 
  • Winding displacements or deformations
  • Winding connection problems
  • Broken clamping structures

Product Details

Transformer Analysis Software:

Windows-based sweep frequency response analysis software is included with each PFRS-25. The software can perform tests automatically and can be used to analyze the test data. The test data can be compared with previous data to analyze any changes. The software graphically compares test results as a magnitude vs. frequency plot, phase vs. frequency graph, or display both graphs at the same time. The software provides an analytical tool that can perform correlation coefficients between two traces per the IEEE C57.149-2012 or DL/T 911-2004 standard.
Users can quickly run tests in the field using pre-defined test connections. These include user-defined configurations as well as configurations defined by the IEEE C57.149-2012 standard. Test data can be exported to XML and EXCEL formats. The PFRS-25 software can import SFRA test records allowing the user to compare the PFRS-25 test records against other devices on the market.

Technical Specifications:

Physical Specifications Dimensions: 13" x 11" x 6" (34 cm x 29 cm x 15 cm)
Weight 10.0 lbs. (4.5 Kg)
Sweep Frequency Range 0.1 Hz - 25 Mhz (selectable)
Input Power 90 - 240 Vac, 50/60 Hz
Sampling Rate 100M samples per second
Sample Points Per Sweep 2,000 points per decade, 32,000 points total
Sweep Time less than 25 seconds (20 Hz - 2 Mhz)
Point Spacing log or linear
Output Voltage 0.2 Vpp - 20 Vpp in 0.2 Vpp steps
Measurement Accuracy ±0.3 dB from 10 dB to -40 dB and ±0.5 dB from -40dB and below
Phase Accuracy 0.1 degree above 50 db
Input Channels 2, 50 Ohm impedance
Output Channels 1, 50 Ohm impedance, short-circuit protected
PC Software Windows®-based analysis software
Computer Interfaces USB and Bluetooth
Software Compatibility Import: CIGRE (*.xfra)
Export: CSV, TXT, CIGRE (*.xfra)
Applicable Standards IEEE C57.149-2012, IEC 60076-18, CIGRE Tech. Guide 342, Chinese DL/T 911-2004
Cables and Clamps Cables: three 30ft (15.2m) 50 Ohm coaxial signal cables, 2 ground straps, power cord
Clamps: 2 voltage cable clamps, 2 ground cable clamps
Optional Battery Backup 12V, 7AH for 3 hours of operation
Temperature Operating: -10°C to +50°C (+15°F to +122°F)
Storage: -30°C to +70°C (-22°F to +158°F)
Altitude 2,000 m (6,562 ft)
Humidity 90% RH @ 40°C (104°F) non-condensing
Warranty One year on parts and labor