The complete set of frequency conversion series resonance test device is a resonant current filtering circuit that can improve the waveform distortion of the power supply, obtain a better sine voltage waveform, and effectively prevent the measured object from being mistakenly broken down by harmonic peak values. The complete set of frequency conversion series resonance test device is in a harmonic state When the insulation point of the test item is damaged, the current will immediately become detuned, and the current in the circuit will quickly drop to one tenth of the normal test current. When flashover and breakdown occur, due to the loss of resonance conditions, except for the immediate decrease in short-circuit current, the high voltage disappears immediately, the arc can be extinguished, and the reconstruction process of restoring voltage is very long. When the flashover voltage is reached again, it is easy to turn off the power again. Therefore, the frequency conversion series resonance test set device is suitable for insulation withstand voltage testing of high voltage and large capacity power equipment.

Practice has proven that the Q value of the test circuit is mainly determined by the characteristics of the reactor. However, in practical work, it has been found that the Q value of the complete set of equipment in the variable frequency series resonance test is usually greater than the Q value provided by the manufacturer in actual use. However, the Q value of the complete set of variable frequency series resonance test devices with voltage levels of 35kV and above is often smaller than the Q value provided by the manufacturer in actual use, and much smaller in severe weather conditions. As the testing time increases, the Q value shows a downward trend. Therefore, the power supply capacity selected based on the Q value provided by the manufacturer cannot meet the requirements of on-site testing, and the voltage cannot reach the withstand voltage value required for testing. It is not difficult to find through analysis that in parameter calculation, the capacitance of the test object and the inductance of the circuit are fixed values, while the variation of Q value is caused by different uncertain factors such as magnetic field interference, wiring, weather effects, reactor characteristics, and placement position.

1) The impact of experimental time

As the experimental time prolongs, the equipment heats up, the equivalent resistance increases, and the Q value decreases. This phenomenon is very significant in summer. To continue testing the entire frequency conversion series resonance test, it is usually necessary for the equipment to rest for 30 minutes.

2) The impact of weather

① When the temperature is high, the equivalent resistance of the circuit increases significantly. Reduce the Q value.

When the humidity is high, the lead corona loss increases significantly, and the interference of the surrounding electromagnetic field also increases, thereby reducing the Q value.

3) The impact of high-voltage leads

In the AC withstand voltage test of a single electrical equipment, due to the small capacitance of the test object, the high voltage lead has little impact on the test. When conducting AC withstand voltage tests in outdoor distribution equipment, the installation height of the equipment increases with the increase of voltage level. The higher the voltage level, the longer the high voltage lead. Generally, the high voltage lead is longer, the corona loss increases, the equivalent resistance of the circuit increases, and the stray capacitance formed by the capacitor is connected in parallel to the tested capacitor, reducing the resonant frequency of the circuit and thus reducing the Q value. This increases the interference of the surrounding electromagnetic field and reduces the Q value. Therefore, in the AC withstand voltage test of high-voltage electrical equipment, corrugated tube high voltage lead is used as much as possible.

4) The impact of reactors

Reactors usually need to be non loss reactors, and if the reactor is poorly processed, it tends to have large losses. In addition, when the reactor is placed on metal parts such as iron plates, eddy current losses will form, and the equivalent resistance will increase.  

The complete set of equipment for frequency conversion series resonance test is widely used in industries such as power, metallurgy, petroleum, and chemical. Suitable for the handover and preventive testing of large capacity and high-voltage capacitor testing items. The Ministry of Electric Power prohibits conducting DC withstand voltage tests on power cables. For friends working in industrial fields such as workshops, I believe that the complete set of frequency conversion series resonance test equipment is not unfamiliar with this instrument, and its appearance is of great help to the speed control of machine operating current.