The AC withstand voltage test design and manufacture of the main electrical equipment such as 10kV cable, main transformer, bus switch and so on. The reactor is designed separately, which not only meets the requirement of high voltage and small current equipment test conditions, but also meets the requirement of low voltage AC withstand voltage test such as 10kV cable. It has a wide application range. It is an ideal withstand voltage equipment for high voltage test departments at prefecture, city and county levels, as well as for power installation and repair engineering units.

The device is mainly composed of variable frequency power supply, excitation transformer, reactor and capacitor voltage divider.

HYG - Refers to the manufacturer code

50 refers to the maximum rated capacity that the equipment can output in units of kVA.

50 refers to the voltage level that the equipment can output, in units of KV

(2) Technical specifications of HYG-50kVA/50kV frequency conversion resonance test device

1. Rated voltage:

25kV - - - meet the AC withstand voltage test of 10 kV cable and motor.

50kV - - - Satisfies 10kV cable AC withstand voltage test;

2. Output voltage waveform distortion rate: <1.0%

3. Allow continuous working hours: 15 minutes of one-time work under rated conditions

4. Device's own quality factor: Q > 50

5. Quality factor of thermal power generator under full load during test: Q > 10 (load-related)

6. Quality factor at full load during cable test: Q > 30 (load-related)

7. Quality Factor of Main Transformer at Full Load Test: Q > 30 (Load-related)

8. Quality factor of GIS, switch and other tests at full load: Q > 50 (load-related)

9. Input power supply: single-phase 380V

10. Frequency regulation range: 20Hz-300Hz

11. Measurement accuracy of the system: 1.5%

12. The device has protective functions such as over-voltage, over-current and zero-position start.

The advantages of series resonance in power system application:

1. The required power supply capacity is greatly reduced. Series resonant power supply generates high voltage and large current by resonant reactor and capacitor resonance. In the whole system, the power supply only needs to provide the active power consumption part of the system. Therefore, the power required for the test is only 1/Q of the test capacity.

2. The weight and volume of the equipment are greatly reduced. In series resonant power supply, not only the heavy high-power voltage regulator and common high-power test transformer are omitted, but also the resonant excitation power supply only needs 1/Q of the test capacity, which greatly reduces the weight and volume of the system, generally 1/10-1/30 of the ordinary test equipment.

3. Improving the waveform of output voltage. Resonant power supply is a resonant filter circuit, which can improve the waveform distortion of the output voltage, obtain good sinusoidal waveform, and effectively prevent the wrong breakdown of the sample by harmonic peak.

4. Prevent large short circuit current from burning fault points. In the series resonance state, when the insulation weakness of the sample is broken down, the circuit immediately detuning and the loop current rapidly drops to 1/Q of the normal test current. When the shunt resonance or test transformer is used for withstand voltage test, the breakdown current increases tens of times immediately. Compared with the two methods, the short circuit current is hundreds of times different from the breakdown current. Therefore, series resonance can effectively find the insulation weakness, and there is no big short-circuit current burn fault point.

5. There will be no recovery overvoltage. When the sample breaks down, because of the loss of resonance condition, the high voltage will disappear immediately, the arc will be extinguished immediately, and the process of rebuilding the recovery voltage is very long. It is easy to disconnect the power supply before reaching the flashover voltage again. This process of voltage recovery is an intermittent oscillation process of energy accumulation, which is long, and no recovery overvoltage will occur.

The main functions and technical characteristics of our FM resonant device are as follows:

1. The device has the protection functions of over-voltage, over-current, zero-position start, system detuning (flashover). The protection value of over-voltage and over-current can be set according to the user's needs. The flashover protection action when the test product flickers down and the flashover voltage value can be recorded for test analysis.

2. The weight of the whole unit is very light, the maximum is not more than 40 kg, which is convenient for field use.

3. The device has three working modes, which make it convenient for users to choose flexibly according to the site conditions and improve the test speed.

The working modes are: full automatic mode, manual mode and automatic tuning manual boost mode.

4. The data number that can be stored and stored is digital, which is convenient for users to identify and search.

5. The starting point of frequency can be set arbitrarily in the prescribed range when the device scans frequency automatically. The direction of frequency scanning can be selected up and down. At the same time, the scanning curve can be displayed on the large LCD screen, so that users can directly understand whether to find the resonance point.

6. Adopting the technology of DSP platform, it can add or subtract functions and upgrade conveniently according to users'needs, and make the man-machine interface more humanized.