Pulsed rotating machine power supplies for electro-thermal-chemical guns

Under U.S. and Marine Corps funding, the Center for Electromechanics has been developing compact, lightweight pulsed rotating machines (compensated pulsed alternators, or compulsators) for electromagnetic guns for the past 10 years. Air-core and iron-core variants of these machines have demonstrated an ability to efficiently drive low impedance pulsed loads. Other advantages of these machines over pulse-forming networks (PFNs) include lower operating voltages, higher burst firing rates, and the ability to store a substantial number of shots in rotor energy. In addition, a wide variety of pulse shapes are possible and the current profile can be varied from shot to shot if needed. This paper describes the important rotating machine power supply design considerations for two operational ETC missions. Aspects of energy storage for burst firing and prime power averaging, pulse shaping capabilities, and switching requirements are also discussed.