The series resonance under UHV power can help many power workers conduct various power tests more conveniently.

With the development of the power system, the capacity of operating equipment continues to increase. For example, the single unit capacity of thermal power units has exceeded 1000MW, and the maximum capacity of hydroelectric units has reached 800MW. If using transmission

The unified testing equipment (power frequency test transformer) is used for AC power frequency withstand voltage testing of these devices. The voltage regulator has a large volume and requires a large testing capacity. It is difficult to solve the problem of large capacity testing power supply on site, so on-site testing is extremely inconvenient. The host of the power frequency withstand voltage tester has advantages in terms of testing power capacity, equipment waveform, and investment. The main unit of the power frequency withstand voltage tester focuses on the potential design and manufacturing of AC withstand voltage testing for hydroelectric generators with a capacity of 250 megawatts and below.

1. Due to full compensation of resonant reactive power, the power of the power supply and equipment is less than 1/10 (1/q10) of the required capacity of the main body; Small in size and light in weight, the device has a large output capacity under the same capacity, but requires a small power capacity. Cheap configuration, safe and convenient operation.

2. Series resonance is actually a current filtering circuit that makes the current passing through the measured body basically the fundamental current, and the waveform distortion rate (THD) of the output voltage is very small, which is superior to all existing AC voltage withstand devices.

3. The short-circuit current after flashover or breakdown of the sample is only 1/10 (1/Q) of the test current before the short-circuit, which can effectively prevent the expansion of the damaged fault point after breakdown.

4. After flashover, the arc will immediately extinguish automatically. The long (second) process of voltage recovery to resonance state after arc extinguishing is a steady-state establishment process, and there is no risk of voltage overshoot or overvoltage recovery in microsecond and millisecond level transient processes.