Frequency response analyzers based can make accurate diagnosis on the transformer internal fault based on the measurement of the characteristic parameters of transformer windings inside, using the frequency response analysis (FRA) method developed and improved by the developed countries.
After the completion of design and manufacture of transformers, the coils and internal structure are finalized, so for the coil of a multi-winding transformer, if the voltage level and winding method are the same, the corresponding parameters (Ci, Li) of each coil shall be determined. Therefore, the frequency characteristics response of each coil also will be determined, so the frequency spectrums of the corresponding coils of three phases are comparable.
During the test of transformer, in case of inter-turn, inter-phase short circuit, or relative coil displacement caused by collisions during transport, as well as coil deformation resulted from electromagnetic tension during operation under short circuit and fault conditions, the distribution parameters of transformer windings will change, which thereby in turn affects and changes the transformers' original frequency domain characteristics, namely the frequency response change in magnitude and the resonant frequency points shift. The transformer winding tester developed according to the response analysis method is the novel NDT equipment for detecting transformer internal fault. It applies to the detection of internal structure fault in 63kV-500kV power transformers.
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Main Technical Characteristics
- Acquisition and control using high-speed, highly integrated microprocessor.
- Communication USB interface used between a laptop and instrument.
- The communication between the laptop and the instrument can use wireless Bluetooth interface or wireless WIFI interface (optional), The wireless WIFI interface can be conveniently used on tablet computers and smart phones.
- Hardware adopts dedicated DDS digital high-speed scanning technology (USA), which can accurately diagnose the faults like winding distorted, bulged, shift, tilt, inter-turn short-circuit deformation and inter-phase contact short-circuit.
- High-speed dual-channel 16-bit A/D sampling (in field test, move tap changer, and the wave curve shows obvious change) .
- The signal output amplitude is adjusted by software, the maximum amplitude peak value is ±10V.
- The computer will automatically analyze the test results and generate electronic documents (word) for saving and printing.
- The instrument has dual measurement features: linear frequency scanning measurement and segment frequency scanning measurement, compatible with measurement mode of two technical groups in China
- The amplitude-frequency characteristics are in line with the national technical specifications on amplitude-frequency characteristics tester. X-coordinate (frequency) has linear indexing and logarithmic indexing, so you can print out the curve with linear indexing and logarithmic indexing. The user can choose either according to actual needs.
- The instrument can fully meet the technical requirements of electricity standard DL/T911-2004 "Transformer winding deformation frequency response analysis".
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Main technical parameters
1.Scan mode:
Linear scanning distribution
Scanning measurement range: (10Hz) - (10MHz) 40000 scanning point, resolution 0.25kHz, 0.5kHz and 1kHz
Segment frequency scanning measurement distribution
Frequency scanning measurement range:
(0.5kHz)-(1MHz),2000 scanning points;
(0.5kHz)-(10kHz)
(10kHz)-(100kHz)
(100kHz)-(500kHz)
(500kHz)-(1000kHz)
2.Other technical parameters:
Amplitude measurement range (-120dB) to (+20 dB)
Amplitude measurement accuracy: 0.1dB
Scanning frequency accuracy: 0.01%
Signal input impedance: 1MΩ
Signal output impedance: 50Ω
Signal output amplitude: ± 20V
Test repetition percent: 99.9%
Measuring instruments dimensions (LxWxH) 300X340X120 (mm)
Instrument's aluminum box size (LxWxH) 310X400X330 (mm)
Overall weight: 18Kg
Packaging: Wooden case filled with foam
Shipping: by Air, Sea, Express, etc.
Shipping time: 7-15 days if it's in stock.
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