Transformer Tan Delta Tester is a kind of instrument with high precision fully automatic measuring the dielectric loss tangent and capacitance of various high voltage electrical equipments in the power plants and substations. The adoption of frequency conversion technology could ensure the accurate measurement in the interference of strong electric field.
b.different frequency: 50D(45Hz/55Hz measure each time) 60D(55Hz/65Hz measure each time) Automatic frequency conversion
고조파 적응
≤3%
신청조건
-15℃－50℃ Relative humidity<80%
치수
460 (L) × 345 (W) × 345 (H)
무게
35kg
Operating principle
After the measuring is started, the high voltage setting value would be transmitted to the variable frequency power supply that would adjust the output to the setting value by the algorithm of PID. The measurement circuit would send the actual measured high voltage to the variable frequency power, finely adjust the low voltage and realize the accurate high-voltage output. According to the setting of positive and negative connection, the measurement circuit would automatic select the input and switch the range based on testing current. Fourier transform is adopted for filtering out interference so as to separate the fundamental wave of signal, make vector operations of the standard current and specimen current, and calculate the capacitance and the tgδ. After repeated measurements, the intermediate result would be selected. After the completion of measurement, the measurement circuit would send step-down instruction to make the voltage of variable frequency power to be reduced to 0 slowly.
Precautions
1. The instrument is only used on power-off equipment. The grounding terminal should be connected to the grounding network reliably.
The instrument should be used in spacious, safe and reliable place.
2. The equipment under test is shifted to the maintenance state if the high-voltage lead is disconnected from operation state and could be cleaned. The instrument could be tested only after good initial insulation test so as to avoid the poor insulation of equipment under test causing the damage of the instrument during the pressing process.
3. The connection mode should be based on the installation of equipment. Corresponding connection mode should be selected in the menu option.
4. The testing voltage level should be selected according to different equipment and the desired voltage should be selected in the corresponding menu option.
5. Under the special circumstances of endangering safety during the testing, the main power supply could be switched off.
6. The connection mode could be changed or the work is done after the power switch on the panel is switched off and the 220V test power is disconnected. If the equipment needs to be retested, you can press the “reset” or select repeat after the completion of previous testing.
7. In order to ensure the measurement accuracy, it is vital to guarantee the good insulation of low-voltage terminal (or secondary terminal) of the equipment and it should be tested in the environment with low relative humidity especially if the small loss of specimen with small capacitance.
8. When making the testing of specimen with large capacitance, the grounding of the instrument and the specimen should not be in the same place to prevent the reverse breakdown voltage or traveling waves which may affect the safety of the instrument.
9. The step-up device is available in the instrument. It is necessary to be careful about the insulation distance of high voltage lead and personnel safety.
10. The instrument must be grounded reliably. Poor grounding may cause danger.
11. After the starting of the instrument, except in special circumstances, the power is not allowed to be turned off suddenly to avoid the over-voltage which may destroy the equipment.
12. Although the HVx special high-voltage wire equipped with the instrument is made factory inspection, it still should be far away from human beings and low-voltage test line. Both the high-voltage core and high-voltage shielding cable are not allowed to be grounded and contact with the low potential of the testing circuit. The core and shielding cable of Cx input line are not allowed to contact with part with high-voltage.
13. The instrument should be protected from the moisture and excessive vibration.
14. The different frequency should be adopted for measuring if the result cannot be confirmed measured by working frequency with too much interferences. Otherwise, working frequency should be used for the measurement.
15. If the measurement result cannot be shown long time(1min) after sending out the measurement instruction, it may be caused by large capacitance of the specimen or crashing of the instrument. You need to restart the instrument, reduce the measurement voltage and make measurement.
16. The instrument has automatic protection feature if it has short circuit.
17. If the paper is extended out from the paper exit on the top of the printer, you need to press the button to stop it. The printing paper could be pulled out.
