Magnetic and conductive shielding for air‐core pulsed alternators in railgun systems

Abstract

Magnetic and conductive shielding are the alternative choices for air‐core pulsed alternators (air‐core CPAs) in electromagnetic railgun systems. Because of the absence of ferromagnetic materials in the air‐core alternators, the flux density inside can be 3–5 T. Electromagnetic shielding is needed to protect the surrounding electronic devices and humans from exposure to high oscillating magnetic fields. Electromagnetic shielding changes the distribution of the magnetic field and the corresponding winding inductance, as well as the output performance of the powering the railgun. This paper mainly concentrates on a GW‐scale, four‐phase air‐core CPA‐based railgun system. The magnetic and conductive shielding are adopted correspondingly. The effectiveness of shielding and electric performance are investigated in detail. Using the co‐simulation method, an instructive comparison is made between the magnetic shield and the conductive shield, which is meaningful to the design of the electromagnetic shielding of air‐core CPAs for railgun systems. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.