On load tap changer testing device for power transformersIntroduction:

Using a variable ratio bridge to measure the transformation ratio of a transformer is cumbersome to operate and has a narrow measurement range, which is no longer suitable for the fast-paced and high-efficiency requirements of modern measurement. The variable ratio tester adopts modern electronic technology and has developed a new generation of fully automatic variable ratio testers, which have the advantages of small size, light weight, high accuracy, and good stability. The ratio tester adopts a large screen LCD Chinese character display and menu operation, with a clear interface. The ratio group can be measured in one go. The ratio tester is an ideal testing instrument for the power industry sector. According to IEC and relevant national regulations, the transformer ratio tester must conduct a transformer ratio test on semi-finished and finished products during the transformer production process, as well as newly installed and overhauled transformers before they are put into operation. In the preventive testing regulations of the Ministry of Electric Power, it is required to regularly measure the transformation ratio of operating transformers. By conducting a transformer ratio test, the turns ratio of the transformer winding and the condition of the tap changer can be checked to determine whether there are defects such as inter turn short circuits in the transformer, and whether it can be operated in parallel, thereby ensuring the safe use of the equipment.

On load tap changer testing device for power transformersSpecification

3.1 Working environment conditions
1. Environmental temperature: -10 ℃ to 40 ℃;
2. Environmental humidity: ≤ 90%;
3.2 Working power supply
1. Single phase voltage: 220 (1 ± 10%) V;
2. Frequency: 50Hz ± 1Hz;
3. Waveform: sine, waveform distortion rate ≤ 2%.
3.3 Internal output test power supply of the instrument
1. Output power frequency: 50Hz ± 0.2Hz (adjustable frequency);
2. Output voltage range: Three phase four wire 0-500V (voltage adjustable);
3. Output capacity: rated 1000VA, large instantaneous output 1500VA; voltage waveform distortion rate:<1%;
4. Voltage phase angle: 120 °, phase angle difference not exceeding 120 °± 1 °.
3.4 Instrument and machine testing accuracy
1. Number of synchronized acquisition channels: 6
2. Data collection accuracy: 16 bits
3. Collection speed: 200 k/s/channel
4. Collection board cache depth: 8 MB byte FIFO
5. Voltage range: 0V to 500V.
6. Current range: 0mA~100mA, 0A~10A;
7. Voltage and current testing accuracy: Level 0.5;
3.5 Insulation performance
1. Insulation resistance: The insulation resistance between the power input terminal and the casing is greater than 20M Ω.
2. The insulation level of the testing device should be able to withstand 1500V AC voltage (effective value)