Product Introduction

   NDBX-Ⅲ Transformer Winding Deformation Tester adopts the internal fault frequency response analysis (FRA) method currently being developed and refined by advanced countries worldwide, enabling accurate diagnosis of internal transformer faults. Once a transformer is designed and manufactured, its coils and internal structure are fixed. Therefore, for a multi-winding transformer coil, if the voltage level and winding method 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 fixed, and the frequency spectra of the corresponding three-phase coils have a certain comparability. If inter-turn or inter-phase short circuits occur during testing, or if collisions during transportation cause relative displacement of the coils, or if electromagnetic forces during operation under short-circuit and fault conditions cause coil deformation, the distribution parameters of the transformer windings will change. This, in turn, affects and alters the original frequency-domain characteristics of the transformer, such as changes in the amplitude of the frequency response and shifts in resonant frequency points.        

   Transformer Winding Deformation Frequency Response Tester quantifies the response changes of internal winding parameters across different frequency domains. Based on the magnitude of these changes, the amplitude, range, and trend of the frequency response variations, it determines the extent of internal winding deformation. This allows for assessing whether the transformer has been severely damaged and whether major repairs are necessary.

Product Features

☆ High-speed, highly integrated microprocessor for data acquisition and control

☆ USB communication interface between PC and instrument

☆ Hardware core utilizes DDS-specific digital high-speed sweep frequency technology (U.S.), enabling accurate diagnosis of winding deformations such as twisting, bulging, displacement, tilting, inter-turn short circuits, and inter-phase contact short circuits through testing

☆ High-resolution dB value measurement, dual-channel 16-bit A/D (field tests show significant output changes when tap changers are adjusted)

☆ Signal output amplitude adjustable via software, with a peak amplitude of ±10V

☆ Utilizes precision, highly stable components; repeatability rate for repeated tests on the same phase exceeds 99.5%

☆ Finished circuit boards with special surface treatment, resistant to water and harmful gas contamination

☆ Laptop and measuring instrument powered by isolated power supplies to eliminate external interference

☆ Dual measurement system functionality: linear sweep frequency measurement and segmented sweep frequency measurement, compatible with both current domestic technical measurement modes

☆ Amplitude-frequency characteristics comply with national technical standards for amplitude-frequency characteristic testers. The horizontal axis (frequency) features both linear and logarithmic scaling, allowing printed curves to be either linear or logarithmic

☆ Automatically generates Word electronic documents for saving and printing

Technical Parameters

☆ Scanning method: (The instrument features dual measurement systems: linear sweep frequency measurement and segmented sweep frequency measurement)

◆ Linear sweep distribution: Sweep frequency range: (1kHz)-(2MHz), 2000 sweep points, resolution of 1kHz

◆ Segmented sweep measurement distribution: Sweep frequency range: (0.5kHz)-(1MHz), 2000 sweep points

                       (0.5kHz)-(10kHz), resolution of 0.02kHz

                       (10kHz)-(100kHz), resolution of 0.2kHz

                       (100kHz)-(500kHz), resolution of 1kHz

                       (500kHz)-(1000kHz), resolution of 1kHz

☆ Amplitude measurement range: (-100dB) to (+20dB)

☆ Amplitude measurement accuracy: 0.1dB

☆ Sweep frequency accuracy: Less than 0.01%

☆ Signal input impedance: 1MΩ

☆ Signal output impedance: 50Ω

☆ Same-phase test repeatability: 99.5%

☆ Instrument dimensions (L x W x H): 345mm x 250mm x 120mm

☆ Aluminum alloy case dimensions (L x W x H): 425mm x 335mm x 215mm

☆ Total weight: 10kg