Wuhan UHV specializes in producingseries resonance (also known as series resonance withstand voltage test device). Below are three common AC test devices introduced to you.

Atpresent, there are three common types of communication testing devices:

1. Power frequency AC withstand voltage device

2. Inductive series resonant withstand voltage device

3. Frequency modulation series resonant withstand voltage test device

Due to its large and bulky size, the power frequency AC withstand voltage device is rarely used on site and is only used during the withstand voltage test of electrical equipment at a voltage level of 10kV.  

The inductive type is abandoned due to its use of adjustable iron core air gap reactors, which have the disadvantages of high noise, complex structure, and bulky equipment. IEC517 and GB7674 consider the test frequency to be basically equivalent to the power frequency voltage test in the range of 10-300Hz. Therefore, most domestic and foreign countries currently use frequency modulation (variable frequency power supply) series resonant withstand voltage devices.

During the experiment, when we choose automatic testing, we can set the parameters such as the test frequency range, test voltage, voltage change step size, excitation transformer ratio, voltage divider ratio, and test time to start the experiment and automatically find the frequency and resonance frequency. When the device finds the resonant frequency, it starts automatically boosting to the target test voltage. After reaching the target voltage, the timer starts, and when the time is up, it automatically steps down and stops.

When we use manual testing, we need to first calculate the frequency using a formula, and then manually increase the voltage.