Compensated pulsed alternators to power electromagnetic railguns

Electric armaments of coilgun or railgun types require repeated bursts of extremely high power (gigawatts), considerable amounts of energy (tens of megajoules), delivered in several milliseconds. Compensated pulsed alternators, due to their high power and energy densities, have emerged as leading candidates for power supplies for railguns of the future. This paper examines test results of completed compulsator-based systems such as the "Cannon Caliber Electromagnetic Launcher", with the objective of formulating estimates of upper bounds to the delivered energy density achievable by rotating electrical machines designed to meet the power requirements of electromagnetic guns. The effects of increasing rotational speeds (for increased energy storage and higher voltage) and of increasing allowable composite material strength and temperature levels on armature-excitation mutual inductances is considered in scaling up machines for application to tank main armament requirements.