Development of 2.4-MJ capacitor bank for electrothermal propulsion technology

A pulsed-power supply of a 2.4-MJ capacitor bank has been developed to investigate electric gun technology by the Agency for Defense Development and some Research Institutes. This is made up of eight 300-kJ modules and can supply various shapes of high-current pulse by controlling the charging voltage, inductance, capacitance, and firing time of each module. The unit module has been designed and fabricated for the maximum operating voltage of 22 kV, the peak current of 150 kA, the pulse duration of 1 ms, and the stored energy of 300 kJ. After the consideration of the characteristics of the main switch, crowbar diode, and the capacitor, the circuit topology of the module was determined. The experiments and the analysis were performed to evaluate the circuit topology. All the modules showed good performance under the condition of the charging voltage of 22 kV, the inductance of 20 μH, and the shorted load. The experiments were performed to verify the parallel operation performances of the modules with the inductance of 20 μH and the load resistance of 100 mΩ, where the modules were discharged simultaneously and/or sequentially. The value of 20 μH was chosen for the permissible peak current and the value of 100 mΩ was chosen as the practical maximum value of the load. The results of the experiments were analyzed. The 2.4-MJ capacitor bank is used for the pulsed power supply for the electrothermal chemical gun.