Research On Trigger System Of Surface-breakdown High-voltage Switch

Pulsed power technology derived from the 1960s, from which, the low power energy is charged fistly, then discharged to the load, through the quick compression and transformation. So, the switch is an important component of the pulsed power system, whose electrical parameters and characteristics have a direct impact on the characteristics of output waveform, such as time delay, amplitude, pulse width, etc. Thesurface-breakdown high-voltage switches proposed in this paper have many advantages, such as, high self-breakdwon voltage, great current, high charge transfer, short time delay, little jitter time, low equivalent inductance, low equivalent resistance, long life, small volume, and etc. A trigge pulse with high rise and high current is needed to turn-on the switch, which will be the precondition for the switch usage.Based on the trigger requirements of the surface-breakdown high-voltage switch, a trigger system of pulse transformer of closed magnet ring is proposed in this paper. Due to the magnetic parameter theory of pulse transformer, the influence of parameters to the output of secondary circuit is analysed, when the secondary circuit is connected to a capacitor parallel. And in ordor to reduce the leakage inductance, the coaxial structure of transformer is adopted. The high-voltage pulse transformor is designed and fabricated,. Meanwhile, the material, dimension, shape and the insulation of the transformer are fixed on.To the design of trigger system, the trigger theory of surface-breakdown high-voltage switches is analysed firstly. Added the experimnents, the influence of trigger current to the time delay and jitter time of switch is obtained. When the trigger current and the rise of trigger current are increased, the time delay and its jitter time are reduced. Besides, according to the trigger requirement of switch, a trigger system of good performance and small volume is fabricated. It can output a pulse voltage of 10kV, trigger current of 600A above, rising time less than 400ns, and life of 20000 shots. It is packaged in a metal box of 110×275×250mm3 at last.The trigger system is used in the three spark gas switch and triggered vacuum switch. The trigger voltage of three spark gas switch is 8~10kV, while its trigger current is 600A, and time delay is 1~10μs. The trigger voltage of triggered vacuum switch is 1~5kV, its trigger current is 300A and its time delay is 1~1.5μs. The rate of trigger successfully is high, and the trigge life is very long. So, the trigger system designed in this paper can meet the demand of engineering application.