Effect of sequence discharge on components in a 600kJ PPS used for electromagnetic launch system

Pulsed Power Supply (PPS) applied in the electromagnetic launch system must have a compact design and high reliability. In this paper, a PPS for electromagnetic launch system has been built up. The main parts in PFU (Pulsed Forming Unit) are energy storage capacitors (8kV/75kJ), pulse-shaping inductor (10µH), pulse thyristor, crowbar diode and a Rogowski coil for current measuring. The energy storage density of the PFU is 0.74MJ/m
³
. Eight PFUs form a PFN of 600kJ. In many cases, the discharge current waveform of PFN must be adjusted for lower peak value and lower electromagnetic force. Based on this PFN, this paper analyzes the effect of the sequence discharge on the semiconductors. To prevent diode from overvoltage during the recovery process, different parameters of snubber circuit have been researched in the experiments. At last, two safe time sequence applied in the 600kJ PFN are confirmed based on simulation.