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.