Influences of Electric Parameters of Pulsed Power Supply on Electromagnetic Railgun System

Abstract

To analyze the electric parameters of a pulsed power supply (PPS) system and their influence on muzzle velocity, a stable and reliable 200-kJ compact PPS system used for electromagnetic railgun system has been developed. The PPS system consists of ten modules, and each module is comprised of a high energy density capacitor (3270 $\mu $ F/3.5 kV), 4-in thyristor, a pulse shaping inductor (1.5 $\mu $ H), and a crowbar diode. At the same time, a railgun circuit model for simulation was established. In this model, velocity skin effect, current skin effect, and friction were taken into consideration. Some electromagnetic launching experiments were carried out to verify the correctness of the railgun circuit model. Influence of different electric parameters of PPS on muzzle velocity was analyzed by the computer aided circuit design program PSPICE based on this model. The parameters include capacitance, equivalent series resistance (ESR) of the capacitor, inductance, and jitter time of the thyristor. The simulation results show that the ESR is the most critical influencing factor (the deviation of velocity is −4.286% when the ESR is 5 m $\Omega $ ). The following is the change of the capacitance (the deviation of velocity is −3.827% when the capacitance decreases to 95%C0). In the meantime, the changes of the resistance of inductor do have an influence on muzzle velocity (the deviation of velocity is −0.908% when the resistance of inductor is 1 m $\Omega $ ). However, the changes of inductance and the jitter time of the thyristor impose no significant effect on muzzle velocity. The conclusions provide reference to the overall optimization of PPS design and quality control of the manufacturing process.