Adjusting Inductance Type Series Resonant Test Set For HV Power Transformer

Adjusting inductance type series resonance test device

1. Subject
For the Suwa Hydropower Station 300MW, the extreme rated voltage is 18kV, the earth capacitance does not exceed 2.58μF, the AC withstand voltage test, the test voltage is 50kV, and the withstand voltage time is 5min.

2. System capacity
For the Suwa Hydropower Station 300MW, the extreme rated voltage is 18kV, the earth capacitance does not exceed 2.58μF, the AC withstand voltage test, the test voltage is 50kV, and the withstand voltage time is 5min. then:
During the test, the high-voltage side current is I=2πfCU=2π×50×2.58×10-6×50×103=40.53A; the rated current of the system is set at 42A, and the rated voltage is set at 50kV, leaving a certain margin.
The overall specification design is 2100kVA/50kV, of which the adjustable reactor is 800kVA/50kV (16A); one fixed reactor, with two parameters of 650kVA/50kV/13H; it can meet the withstand voltage requirements of the 0～2.58μF test product.
In summary: 2100kVA/50kV can meet the withstand voltage requirements of 2.54μF test product

3. The main technical parameters and functions of the system
1. Rated capacity: 2100kVA;
2. Rated voltage: 50kV;
3. Rated current: 42A;
4. Working frequency: power frequency 50Hz;
5. The output voltage waveform distortion rate: ≤1%;
6. Allowed continuous working time: 5min under rated load, 1.1 times overvoltage for 1 minute;
7. The temperature rise after continuous operation for 5 minutes under rated load is ≤65K;
8. The quality factor of the device itself: Q≥30;
9. High pressure measurement accuracy: effective value 1.5;
10. Input power: three-phase 380V voltage, frequency 50Hz;
11. The test product has overcurrent, overvoltage and test product flashover protection functions;
12. Ambient temperature: -250C-450C, relative humidity: ≤90%RH, altitude ≤3200 meters.

4. Introduction to the principle of series resonance
The series resonance test system is a device used to perform AC withstand voltage tests on various capacitive test products. It is characterized by greatly reducing the capacity of the input power required for the test, reducing the volume and weight of the test equipment, making the field test easy to implement; and greatly reducing the labor and material costs of the test equipment and the input required for the test.
Fanke has been engaged in the development and production of high-voltage test equipment for more than 20 years, and the resonant system is the flagship product of Fanke. At present, hundreds of resonant systems produced by Fanke have been successfully used in various fields of power systems at home and abroad.
The series resonance system is divided into tuned inductance resonance and frequency modulation resonance. The two resonances achieve resonance in different ways. The tuned inductance type makes the test circuit resonate by adjusting the inductance, while the frequency modulation type makes the test circuit resonate by adjusting the test frequency. . But the result is the same, that is, the large-capacity output required by the test product can be obtained by inputting a small-capacity power supply. The principle diagram of resonance is shown in Figure