Design and Analysis of Air Core Outer Rotor Halbach Array Compulsator

Conventionally, the capacitor-based pulsed power supply is used for the railgun. However, it cannot create zero current crossings during discharge, which leads to a large muzzle arc. This invariably leads to compulsator as a popular choice for railgun pulsed power supply. Moreover, the size of compulsator is comparatively lower than a capacitor bank of the same energy. A computer-aided design (CAD) of 10-MJ, 4-phase, 4-pole compulsator for achieving desired performance is developed and presented in this article. A six-segment Halbach array is adopted for permanent magnet (PM) excitation to remove the slip ring arrangement and to reduce voluminous design due to external excitation. The designed compulsator is simulated in Ansys electromagnetic (EM) suite for field analysis with practical design considerations along with the inclusion of armature winding impedance, PM demagnetization effects, and eddy current distribution in compensating shield. The railgun circuit analysis is carried out for the designed compulsator co-simulated using Simplorer and Ansys EM. Furthermore, various parametric studies are conducted for designed compulsator to analyze the effects on the acceleration and synchronization of the projectile’s exit from the barrel. Detailed simulation results show that the target specifications are achieved with the new design.