Years of practical experience in power testing and inspection have taught us that onlyvariable frequency series resonant withstand voltage testing devicescan meet the preventive testing of insulation performance for large capacity power equipment. Due to the high voltage level of large capacity power equipment and the need for large capacitors, general power frequency withstand voltage test devices are no longer able to meet the withstand voltage test requirements of large capacity power equipment. Due to the greatly reduced capacitance of the variable frequency series resonance, the required power supply for testing is only 1/Q of the testing capacity (q is the quality factor). Therefore, by using a variable frequency series resonance testing device, it is easier to increase the voltage to the required power level.
It is safer and more reliable to use avariable frequency series resonant withstand voltage test devicefor the withstand voltage test of large capacity power equipment. Due to the strong protection function and good stability of the variable frequency power supply, the testing device has multiple testing modes including fully automatic testing, automatic tuning and boosting, fully manual testing, manual tuning and boosting, semi-automatic testing, etc. Therefore, testing operations are more convenient and secure.
Can prevent large short-circuit currents from burning out the fault point. In the state of series resonance, when the weak insulation of the tested object is broken down, the circuit will immediately eliminate harmonics, and the circuit current will quickly decrease to 1/Q of the normal test current. However, when parallel resonance or test transformer is used for voltage withstand test, the breakdown current will immediately increase by tens of times. Compared with the two methods, the short-circuit current and breakdown current differ by hundreds of times. Therefore, series resonance can effectively detect weak insulation points without worrying about large short-circuit currents burning out the fault points.
The use of avariable frequency series resonant withstand voltage test devicewill not result in overvoltage recovery. When the sample breaks down, due to the loss of resonance conditions, the high voltage immediately disappears and the arc immediately extinguishes. Moreover, the process of re establishing the restoration voltage is very lengthy. It is easy to disconnect the power supply before reaching the flashover voltage again. The recovery process of this voltage is an intermittent oscillation process of energy accumulation, which takes a long time and does not result in overvoltage recovery.
To ensure the safety test of variable frequency series resonance and improve test efficiency, the following aspects should be noted:
1. During the use of the variable frequency series resonant withstand voltage device, attention should be paid to avoiding storage and high temperature. The frequency conversion series resonance withstand voltage test device should be used in high humidity, flammable, explosive, and strong magnetic field environments.
2. When repairing the frequency conversion series resonance withstand voltage test device, wet cloth and neutral cleaning agent should be used to clean the device housing, and abrasives and solvents should not be used.
3. Before operation, it is necessary to check whether the frequency conversion series resonance withstand voltage test device is intact and whether the connecting wires are intact to ensure the safe connection of the power output and signal sampling cables, and to carry out the test without any faults. Resistance.
4. Before using the frequency conversion series resonance withstand voltage test device, the wiring must be accurate, especially the grounding circuit must be safely grounded;
5. When using a variable frequency series resonant withstand voltage test device for testing, it is not allowed to suddenly cut off the power supply. The power supply can only be disconnected when the variable frequency series resonant withstand voltage test device exits the test state in each test.
Wuhan UHV specializes in the production ofseries resonance (also known as AC withstand voltage test device)and has been engaged in the electrical measurement industry for many years. Its products have first-class quality and welcome customers to come and purchase.
