Darui Electric recommends for youSafety Work GuidelinesBefore using the transformer winding tester, please read this chapter carefully to familiarize yourself with important safety points and warnings.
Follow the instructions in this manual to use the tester; otherwise, the protection provided by the tester may be impaired.
In this manual:
[Warning] refers to situations or operations that pose a danger to the user or the instrument.
[Caution] refers to situations or operations that may cause damage to the tester or the transformer under test.
[Note] refers to situations or operations that may cause errors in test results.
To avoid personal injury and damage to the tester or transformer under test, follow these guidelines:
[Warning] The transformer core must be reliably grounded to the enclosure. The tester enclosure and measurement impedance enclosure must be reliably grounded to the transformer enclosure.
[Warning] Do not start the winding deformation test until the tester's "ground" is correctly connected.
[Warning] Before testing, fully discharge the transformer terminals.
[Note] Before use, check the appearance of the tester and verify that the power switch is in the "Off" position and all terminals are normal.
[Note] The winding deformation test should be performed after disconnecting all transformer leads (including overhead lines, enclosed busbars, and cables), and keep these leads as far away from the transformer bushings as possible (grounding bodies and metal floating objects should be at least 20 cm away from transformer bushings), especially for transformers connected to enclosed busbars.
[Note] During testing, correctly record the tap changer position. Place the tap changer of the transformer under test at the first tap if possible, especially for on-load tap-changing transformers, to obtain comprehensive winding information. For off-load tap-changing transformers, ensure each measurement is at the same tap position for comparison.
[Note] Ensure that the measurement impedance clamps are in tight contact with the bushing terminals. If there is conductive grease or rust on the bushing terminals, clean them with sandpaper or a dry cotton cloth.
Technical Features:Testing can be performed without lifting the cover or disassembling the transformer.
Uses the currently most popular sweep frequency method for measurement.
This instrument can measure transformers above 6kV.
Adopts a split structure; the test host connects to the main control computer via USB, plug-and-play.
Simple on-site wiring and easy to use.
Wide measurement dynamic range: -100dB to 20dB.
Powerful analysis software; software and hardware indicators meet the national standard DL/T911-2004.
Main technical specifications of the Transformer Winding Deformation Tester (Frequency Response Method):
Test host to PC interface: USB.
Signal source: The instrument has one channel signal output as the sweep excitation signal; the signal output is a standard sine wave with adjustable amplitude via software, maximum amplitude ±10V, output impedance 50Ω.
Two acquisition channels: one for excitation signal and one for response signal, used to calculate the transfer function.
Acquisition channel quantization accuracy: 14 bits.
Maximum storage capacity per channel: 64K samples.
Maximum sampling rate per channel: 25Msps.
Acquisition channel input impedance: 1MΩ.
Sweep frequency measurement range: 500Hz – 2000kHz.
Scanning method: Linear distribution sweep measurement.
Scanning frequency accuracy: The frequency accuracy of the sine signal output from the signal source is no greater than 0.01%.
Sweep measurement frequency points: Fixed mode or user-defined.
Complies with national electric power industry standard: DL/T911-2004.
Main features of the test analysis software:
Based on Windows platform, compatible with Windows 2000/Windows XP.
Can load up to 2 curves simultaneously; relevant parameters of each curve are automatically calculated, and winding deformation is automatically diagnosed, providing a diagnostic reference conclusion.
Powerful software management functions, fully considering on-site needs; automatically saves environmental condition parameters to provide a basis for transformer winding deformation diagnosis. Measurement data is automatically saved; color printing function is available for users to generate test reports.
The software is highly user-friendly; most measurement conditions are selectable options, requiring minimal input on-site, making it more convenient for users.
High software intelligence; after connecting input and output signals, all measurement tasks can be completed with just one button.
The software interface is simple and intuitive.
System IntroductionThe Transformer Winding Deformation Tester (Frequency Response Method) is used to test power transformers of 6kV and above voltage levels and other special-purpose transformers. Power transformers inevitably suffer from various fault short-circuit currents or physical impacts during operation or transportation. Under the strong electrodynamic forces generated by short-circuit currents, transformer windings may lose stability, leading to local distortion, bulging, or displacement and other permanent deformation phenomena, which will seriously affect the safe operation of the transformer. According to the national electric power industry standard DL/T911-2004, the frequency response analysis method is used to measure transformer winding deformation. It detects the amplitude-frequency response characteristics of each transformer winding and performs longitudinal or horizontal comparison of the test results. Based on the degree of change in the amplitude-frequency response characteristics, it determines the possible deformation of the transformer winding.
The Transformer Winding Deformation Tester (Frequency Response Method) consists of a measurement part and an analysis software part. The measurement part is a black box composed of signal generation and signal measurement, while the analysis part is completed by a laptop. The measurement part connects to the laptop via USB or network.
PreparationNote: Basic operations involving the computer and Windows operating system in the user manual are not covered in this manual; please refer to relevant computer books.
Note: Basic operations of the Windows operating system in this manual are based on Windows XP; differences between Windows 2000 and Windows XP operations are not covered in this manual; please refer to relevant computer books.
Installation of USB Driver for Acquisition Instrument
Driver Installation
After connecting the hardware circuit to the computer, if it is the first connection, the computer will prompt that a new device has been found. Insert the driver CD into the computer and proceed with driver installation. When the hardware circuit is first connected to the computer, the microcontroller on the card does not have a program yet; its default ID is: VID:0x04B4; PID:0x8613. Through this ID, the computer finds the wdgtldr.sys file, which contains the microcontroller program. It transfers the microcontroller program to the microcontroller on the acquisition card via a certain method and runs it. After that, the microcontroller has a new ID, through which the computer finds the ezusb.sys file. The ezusb.sys file is provided by Cypress and supports USB data transfer; in the application software, data transmission and control are carried out through it. Due to the use of online loading technology in the system design, the new hardware will be found twice; follow the prompts to proceed.
Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.
