Use of SABER circuit simulation software for the modeling of compensated pulsed alternators driving a railgun load

Abstract

A railgun launcher requires very high current pulsed power over the period of a few milliseconds. For laboratory systems, capacitor banks have traditionally been used to provide this energy, but field applications require a system with significantly higher energy storage density. Rotating machines that store the energy in the form of rotational kinetic energy and can quickly convert that energy to high current electrical energy have been designed and built. These low-impedance, multiphase, multipole synchronous generators are referred to as pulsed alternators. The AC output of the pulsed alternator is rectified to provide DC to power the railgun. The design of the rectifier set and control circuitry is very dependent on the alternator characteristics; to facilitate the design and evaluation of the overall pulsed power system, a modeling tool which accurately represents the performance of the pulsed alternator while allowing easy changes to the external circuitry and controls is needed. This paper describes a manner in which these pulsed alternators can be accurately modeled. The simulation platform SABER was chosen because of the robust modeling engine, the ease of integrating mechanical components, and the large library of existing models for a wide range of electrical components.