An overview,

Transformer winding deformation tester (impedance method) is an intelligent instrument specially used for measuring the impedance characteristics of large and medium-sized transformers. Article 15.2 of twenty-five Key Requirements for Preventing Major Accidents in Electric Power Production issued by The State Electric Power Company in Document no. 589 [2000] stipulates: "Transformers of 110KV and above voltage grade shall be subjected to low voltage short-circuit impedance test or winding deformation test by frequency response method before they leave the factory and go into production to keep the original records. As stipulated in 15.6, "after the transformer is subjected to sudden short-circuit near the area, the low-voltage short-circuit impedance test or the frequency response method should be used to test the winding deformation, and compared with the original record, judging that the transformer has no fault, before it can be put into operation." Low voltage short circuit impedance measurement can accurately reflect the change of transformer impedance before and after winding deformation. The test instrument adopts voltage and current high-precision synchronous AC sampling and FFT digital signal processing technology, the measurement data is accurate and stable. The instrument adopts three-phase automatic measurement or single-phase measurement, the low-voltage side is reliably short-connected, input transformer parameters, the instrument can automatically test, automatically calculate each phase impedance and impedance error percentage, the test results are very intuitive. Display voltage and current waveform during testing, more suitable for field use.

The system is composed of measurement part and analysis software part. The analysis part is completed by the laptop computer, and the measurement part is connected with the laptop computer through USB cable.

Two, main technical parameters

Measuring speed: 1-2 minutes for single-phase winding

Output voltage: VPP-25V, automatic adjustment during test

Output impedance: 50 ω

Input impedance: 1M ω (response channel built-in 50 ω matching resistor)

Frequency sweep range: 10Hz to 2MHz

Frequency accuracy: 0.001%

Sampling frequency: 100Msps

Sweep mode: linear or logarithmic, sweep interval and points can be set arbitrarily

Curve display: amplitude frequency curve

Wide measurement dynamic range: -120dB ~ 20dB

Impedance method (low voltage method) : measuring voltage: 0 ~ 220V, measuring current: 0 ~ 10A (front panel)

Impedance method (external power supply method) : measuring voltage: 100V ~ 500V, measuring current: 10A ~ 50A (rear panel)

Impedance method frequency: 50Hz/60Hz