This device can designed for AC voltage withstand test for
11kV/30MW hydroelectric generator. It is composed by frequency
power source, excitation transformer, reactor, capacitance divider.
The advantages of serial resonant system:
1.Need smaller power capacity. The power of the serial resonant
system generate high voltage and high current by resonant reactor
and measured capacitance, in the whole system, power source only
provides the power consumption part of the system, so the required
power is only 1/Q of the measured capacity.
2.Lighter and smaller volume. Without the heavy power voltage
regulating device and test transformer, and excited power is only
1/Q of the measured capacity. The weight and volume are only
1/10-1/30 of the common devices.
3.Improve the output voltage waveform. Resonant power source is
resonant filter circuit, which can improve the output voltage
waveform distortion, get better sin wave, and effectively prevent
the harmonic peak value breakdown the measured equipment.
4.Prevent the high current to burn out the fault point, for the
serial resonant; the circuit will be dissonant as soon as the
insulation weakness of the measured device was broken down, the
loop current fast decrease to the 1/Q of the normal measured
current. But for the parallel resonant or test transformer to do
voltage withstand test, the breakdown current , these two compare,
short circuit current and breakdown current different in hundreds
times. So the serial resonant system can easily find out the
insulation weakness, and do not worry about the heavy short circuit
current burn out the fault point.
5.Without any recovery over-voltage. When the measured equipment
was broken down, it lost the resonant conditions, high voltage
immediately disappear, electric arc immediately burn out, and it is
a long process to recover the voltage, easily to power off before
it get to the flashover voltage another time, it is a long process,
without any recovery over-voltage.
