Triggered Vacuum Gaps in a High Power Three-Phase Synthetic Test Circuit

In a three-phase synthetic test circuit triggered vacuum gaps (TVG´s) are applied as fast switches. To discharge the six capacitor banks (50 kV, 12.5 kJ) of the reignition installation in that test circuit, sealed-off TVG´s are used with a glass-ceramic surface trigger. To switch on a low oscillating current in each phase of the voltage injection installation, three continuously pumped TVG´s are used with a polyacetal evaporating trigger. Because of a selfgenerated axial magnetic field of 10 mT/kA this TVG is also capable of switching a high current of 14 kA rms (50 Hz) during the first 4 ms. Since 1982 both types of TVG´s are operational in a 145 kV, 50 kA three-phase synthetic test circuit at KEMA High Power Laboratories.