Introduction:
Based on the measurement of internal winding characteristic parameters of transformers, this transformer winding deformation tester adopts the Frequency Response Analysis (FRA) method, which is being developed and perfected in developed countries worldwide, to accurately diagnose internal faults in transformers.
Once a transformer is designed and manufactured, its coils and internal structure are fixed. Therefore, for a multi-winding transformer, if the voltage levels are the same and the winding methods are identical, the corresponding parameters (Ci, Li) of each coil should be determined. Consequently, the frequency domain characteristic response of each coil is also fixed, and the frequency spectra among the three-phase coils have a certain comparability.
During testing, if inter-turn or phase-to-phase short circuits occur, or if the transformer experiences impacts during transportation causing relative displacement of coils, or if electromagnetic forces during short circuits and fault conditions cause coil deformation, the distributed parameters of the transformer windings will change. This in turn affects and alters the original frequency domain characteristics of the transformer, such as amplitude changes in frequency response and shifts in resonant frequencies. The HTBX-H Transformer Winding Frequency Response Tester, developed based on the response analysis method, is precisely such a novel non-destructive testing device for internal faults in transformers. It is suitable for detecting internal structural faults in power transformers rated from 63kV to 500kV.
It quantifies the response changes of internal winding parameters at different frequency domains, and based on the magnitude of change, the amplitude, region, and trend of frequency response variations, it determines the degree of change in the internal windings. This allows for judging whether the transformer has been severely damaged and whether major repairs are necessary.
For transformers in operation, regardless of whether frequency domain characteristic graphs were previously saved, by comparing the differences in characteristic spectra among the coils of a faulty transformer, the extent of the fault can also be assessed. Of course, if a set of original winding characteristic graphs is preserved, it provides even more precise and powerful evidence for evaluating the operating condition, post-accident analysis, and maintenance planning of the transformer.
The Transformer Winding Deformation Frequency Response Tester consists of a laptop computer and a microcontroller, forming a high-precision measurement system. It is compact, easy to operate, and has comprehensive testing and analysis functions. Users can operate it independently after referring to the instruction manual or receiving short-term training.
Product Aliases: Power Transformer Winding Deformation Tester, Transformer Winding Deformation Detector, Transformer Winding Deformation Measuring Instrument, Transformer Winding Deformation Analyzer
Technical Specifications:
The instrument comes with one channel of DDS signal output as the sweep excitation signal; the signal output is a sine wave, and the output amplitude can be adjusted via software, with a maximum amplitude of ±5V and an output impedance of 50Ω.
Two acquisition channels: one for the excitation signal and one for the response signal, used to calculate the transfer function.
The excitation channel measurement has a fixed range: ±5V; the response channel has 8 ranges, which are automatically adjusted during measurement, with a maximum input signal of ±25V.
Acquisition channel quantization accuracy: 12 bits.
Maximum static error of acquisition channels: 0.5%.
Maximum storage capacity per channel: 64K samples.
Maximum sampling rate per channel: 20 Msps.
Input impedance of acquisition channels: 1MΩ.
Sweep frequency measurement range: 1K-1MHz.
Sweep mode: linear distribution sweep measurement.
Sweep frequency accuracy: the frequency accuracy of the sine signal output by the signal source is not greater than 0.01%.
Sweep frequency measurement points: 1K-1MHz, with 1000 measurement points.
Uses Vittal original chassis.
Complies with national power industry standard: DL/T911-2004.
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