One、Product overview
This device principal for 220KV/25000KVA Main transformer neutral point AC
voltage withstand test. The reactor is designed to meet the requirements of low voltage
AC voltage test, such as high voltage and low voltage, and it can meet the requirement of
low voltage AC voltage test with 10kV cable.
The device is composed of a frequency conversion control power supply, an excitation
transformer, a reactor, a capacitor voltage divider, and a compensating capacitor.
1.1 Application of series resonance in power system:
1.1.1、The required power capacity is greatly reduced. Series resonant power supply is
the use of the resonant reactor and the capacitor voltage to generate high voltage
and high current. In the whole system, the power supply is only required to provide
active power consumption of the system, therefore, the power required to test the
power is only 1/Q.
1.1.2、The weight and volume of the device is greatly reduced. The series resonant power
supply, not only saves large power heavy pressure adjusting device and ordinary
power frequency test transformer and resonant excitation power supply only needs to
test the capacity of 1/Q, which makes the system weight and volume greatly reduced,
generally for ordinary test device 1/10.
1.1.3、Improve the output voltage waveform. Resonant power supply is a resonant filter
circuit, can improve the output voltage waveform distortion, get a good sinusoidal
waveform, effectively preventing the harmonic peak of the test sample of the false
breakdown.
1.1.4、Prevention of large short-circuit current burn. In series resonant state, when the
insulation of the test sample is breakdown, the circuit is immediately removed, and
the loop current is rapidly decreased to the normal test current 1/Q. And parallel
resonance or test transformer mode to do the test, the breakdown of the current rise
in a few times, the difference between the short circuit current and the breakdown
current of several hundred times. Therefore, the series resonance can effectively find
the insulation weakness, and there is no big fault point of the fault of the short circuit.