RAILGUN MODELING WITH THE P-SPICE CODE

Starting from the conventional modeling of the railgun as an electrica l circuit coupled to a mechanical system, we have developed our own mo del including detailed behavior of aspects of electrical components su ch as non linearity of the resistance, charge accumulated in semicondu ctors. This permits an accurate modeling of sensitive devices like swi tching semiconductor diodes (crowbar), In a second approach, we incorp orated the velocity skin effect by using a one dimensional approximati on, The results are compared to measurements obtained on a DES (Distri buted Energy Storage) capacitor driven railgun (PRESTUDY PEGASUS) with a stored energy of 2.8 MJ and a 50 mm round bore, The calculated curr ents and velocity are in good agreement with the measurements. Voltage s and energy distribution in different parts of the circuit are also c ompared, to obtain information of the loss mechanism in our railgun. F ault analysis of the switching modules is also described.