Transformer winding deformation tester

Transformer winding deformation testersummary:

Based on the measurement of the characteristic parameters of the internal winding of the transformer, the internal fault frequency response analysis currently being developed and improved by developed countries in the world is adopted(FRA)Method to accurately diagnose internal faults in transformers.

After the completion of transformer design and manufacturing, its coil and internal structure are determined. Therefore, for a multi winding transformer coil, if the voltage level is the same and the winding method is the same, the corresponding parameters for each coil are determined(CiTheLi)It should be certain. Therefore, the frequency domain characteristic response of each coil is also determined, and the corresponding frequency spectra between the three-phase coils have a certain comparability.

During the testing process, if a transformer experiences inter turn or inter phase short circuits, or if it collides during transportation, causing relative displacement of the coil, and if the coil deforms due to electromagnetic tension during short circuits and fault states during operation, the distribution parameters of the transformer winding will change. Furthermore, it affects and alters the original frequency domain characteristics of the transformer, such as amplitude changes in frequency response and harmonic frequency point shifts. The transformer winding tester developed based on response analysis method is a novel non-destructive testing equipment for internal faults of transformers. It is suitable for63kV～500kVInternal structural fault detection of power transformers.

The instrument quantifies the response changes of the internal winding parameters of the transformer in different frequency domains, and determines the degree of change in the internal winding of the transformer based on the magnitude of the changes, the amplitude and region of the frequency response changes, and the trend of the frequency response changes. 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 feature maps have been saved in the past, the degree of fault can also be determined by comparing the differences in feature maps between faulty transformer coils. Of course, if a set of original winding characteristic maps of the transformer is saved, it is easier to provide more accurate and powerful basis for the operation status, post accident analysis, and maintenance of the transformer.

The instrument consists of a laptop and a microcontroller to form a high-precision measurement system,The structure is tight, the operation is simple, and it has a relatively complete testing and analysis function. It can be operated and used by referring to the user manual or after short-term training.

Transformer winding deformation testerTechnical Features:

The acquisition control adopts high-speed and highly integrated microprocessors.

Laptop computer throughUSBInterface and instrument connection usage.

The instrument automatically analyzes and judges the detection results, and generates electronic documents(Word)For storage and printing.

This instrument meets the power standards simultaneouslyDL/T911－2016The technical requirements of the frequency response analysis method for deformation of power transformer windings,

High speed dual channel16bitA/Dsampling(On site testing changed the tap changer, and there was a noticeable change in the waveform curve).

The hardware core of the frequency response method adoptsDDSSpecialized digital high-speed frequency scanning technology(the United States)Through testing, it is possible to accurately diagnose faults such as winding distortion, bulging, displacement, tilting, inter turn short circuit deformation, and phase to phase contact short circuit.

The frequency response method has dual measurement system functions of linear sweep frequency measurement and segmented sweep frequency measurement,Compatible with measurement modes of two current domestic technological schools.

The amplitude frequency characteristics of the frequency response method comply with the technical specifications of the national amplitude frequency characteristic tester. The horizontal axis (frequency) has two types of divisions: linear division and logarithmic division, so the printed curve can be a linear division curve or a logarithmic division curve, and users can choose according to their actual needs.

Technical Specifications:

scanning method

Linear scanning distribution

Sweep frequency measurement range:(10Hz)-(10MHz)40000Scan frequency point, resolution:0.25kHzThe0.5kHzand1kHz.

Segmented sweep frequency measurement distribution

Sweep frequency measurement range:(0.5kHz)-(1MHz)、2000Sweep frequency point;

(0.5kHz)-(10kHz)

(10kHz)-(100kHz)

(100kHz)-(500kHz)

(500kHz)-(1000kHz)

Other technical parameters

Range of amplitude measurement: (-120dB)to(+20dB)

Accuracy of amplitude measurement: 0.1dB

Scanning frequency accuracy: 0.01%

Signal input impedance:1MΩ

Signal output impedance:50Ω

Signal output amplitude: ±20V

Repetition rate of in-phase testing:99.9%