Power conditioning for pulsed high voltage generation from capacitor bank by using fuse opening switch (FOS) and tape-wound transformer

Abstract

Summary form only given, as follows. When pulsed power is supplied to a high-impedance load from a capacitor bank, power-conditioning devices are required in order to convert slow high-current into fast high-voltage. Most widely used power-conditioning devices are opening switches, closing switches, and transformers. We designed a fuse opening switch (FOS) and a tape-wound transformer to obtain a high voltage pulse from a capacitor bank. The FOS was made of a layer of copper foil as a fuse and two layers of PTFE (ploytetrafluoroethylene) films as a quenching medium. The copper foil was sandwiched tightly with two PTFE sheets by adhesive tape. An air-core type transformer was adopted in order to avoid problems associated with high magnetic field. Copper sheets coated two times with polyester films were wound by 1 turn for the primary and 165 turns for the secondary coils of the transformer. We assembled the capacitor bank, the FOS, the transformer, and a resistive load, in series, and tested the assembled system. Peak current of 150 kA was supplied from the capacitor bank of 75 /spl mu/F charged at 19 kV to the primary coil of the transformer through the FOS. The current was rapidly interrupted by rupture of the FOS, and induced high di/dt and consequently high voltage, 38 kV at the primary coil and 330 kV at the secondary coil of the transformer connected to a resistive load of 300 /spl Omega/. The FWHM (full width half maximum) of the load voltage was 0.9 /spl mu/s.