The Transformer Winding Deformation Tester, based on the measurement of characteristic parameters of the internal windings of a transformer, adopts the internal fault frequency response analysis (FRA) method that is being developed and perfected in developed countries around the world, enabling accurate judgment of internal faults in transformers. After the transformer design and manufacturing are completed, its coils and internal structure are determined. Therefore, for a multi-winding transformer coil, if the voltage levels are the same and the winding methods are the same, the corresponding parameters (Ci, Li) of each coil should be determined. Consequently, the frequency domain characteristic response of each coil is also determined, and the frequency spectra of the three-phase coils have a certain comparability. During testing, if inter-turn or phase-to-phase short circuits occur, or if collisions during transportation cause relative displacement of the 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 the frequency response and shifts in resonance frequencies. The Transformer Winding Frequency Response Tester, developed based on the response analysis method, is such a novel non-destructive testing device for internal faults in transformers. It is suitable for detecting internal structural faults in power transformers from 63kV to 500kV. The Transformer Winding Deformation Tester quantifies the response changes of internal winding parameters in different frequency domains, and based on the magnitude of changes, the amplitude of frequency response variations, the region, and the trend of frequency response changes, it determines the degree of deformation of the internal windings. Based on the measurement results, it can then determine whether the transformer has been severely damaged and whether major repairs are needed. For transformers in operation, regardless of whether frequency domain characteristic graphs have been previously saved, by comparing the differences in characteristic spectra between the coils of a faulty transformer, the degree of fault can also be judged. Of course, if a set of original winding characteristic graphs of the transformer is preserved, it provides a stronger basis for assessing the operating condition, post-accident analysis, and maintenance and repair 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 in structure, simple to operate, and has relatively complete testing and analysis functions. It can be operated by following the instruction manual or after short-term training.
Also known as: Power Transformer Winding Deformation Tester, Transformer Winding Deformation Detector, Transformer Winding Deformation Measuring Instrument, Transformer Winding Deformation Analyzer
1. The acquisition control adopts a high-speed, highly integrated microprocessor
2. Communication between the laptop and the instrument via USB interface
3. Communication between the laptop and the instrument via wireless Bluetooth interface
4. The hardware core uses DDS dedicated digital high-speed frequency sweep technology (from the United States), which can accurately diagnose faults such as winding distortion, bulging, displacement, tilting, inter-turn short circuit deformation, and phase-to-phase contact short circuits through testing
5. High-resolution dB value measurement, dual-channel 16-bit A/D (changing the tap changer during field tests results in obvious output changes)
6. The signal output amplitude can be adjusted by software, with a maximum peak value of ±10V
7. The computer generates electronic documents (Word) from the test results
8. Precision, high-stability components are selected; for repeated tests on the same phase, the measurement repeatability rate is above 99.5%
9. The finished circuit board has special surface treatment, resistant to water and harmful gas pollution
10. The instrument has dual measurement system functions of linear frequency sweep measurement and segmented frequency sweep measurement, compatible with the measurement modes of two current domestic technical schools
11. The amplitude-frequency characteristics comply with the national technical indicators for amplitude-frequency characteristic testers. The horizontal coordinate (frequency) has both linear and logarithmic scales, so the printed curves can be either linear or logarithmic, depending on the user's actual needs
