A novel crowbar scheme for capacitive pulsed power systems

Summary form only given, as follows. Capacitive pulsed power systems are based on the RLC circuits. According to the magnitude of the load resistance and the circuit characteristic impedance, the load current or capacitor voltage may swing or not. The current or voltage oscillation is often not allowed due to the load property or the voltage reversal limit of the energy storage capacitors. Crowbar circuits are inserted for the suppression of the oscillation in these cases. Usually diodes are used as a crowbar switch but when the system voltage and current become high it is not a practical system because the cost of the diodes goes up enormously. A novel crowbar scheme using a spark gap or vacuum gap switch which was triggered at a proper time after the current peak was proposed, implemented and tested. A Rogowski coil was used for sensing the current peak. Because the output of a Rogowski coil shows generally the time derivative of the current waveform, a diode inserted in parallel to the output signal can clamp the positive part of the induced voltage signal of the Rogowski coil. When the voltage arrives at a proper negative value, a square pulse voltage signal of 15 V which triggers the trigger generator for the gap switch for crowbarring can be produced through an amplifier circuit. The implemented circuit shows successful crowbarring actions at a RLC circuit of 1236 /spl mu/F, 160 /spl mu/H, 100 mOhm with the capacitor charged up to 17 kV, the peak current of 34 kA and the capacitor voltage reversal of 1.8 kV.