A Revised Inductance Distribution Analysis of Medium-Large Caliber
Electromagnetic Launchers including a Large Bus Structure
Abstract
An important application for large-scale pulse power supplies (PPS) is
electromagnetic launchers (EMLs). These de- vices utilized stored
several MJs of electrochemical energy into linear mechanical energy.
Because of extreme physical conditions, simulations are crucial in
electromagnetic launcher (EML) research. As the operation risk rises,
more en- ergy into the system adds weight to the model’s accuracy. In
this paper, the electromagnetic impact of the bus structure is
discovered in a recently developed EMFY-3 electromagnetic launcher, is
presented. An H-shaped bus structure is used for the current injection.
However, experiments showed that the H-shaped bus changes inductance
calculations. A careful examination is made to reveal the physical
reasoning behind the bus impact. We hypothesize that the rail portion
surrounded with bus geometry has less inductance than the rest due to
the eddy current created by rail current transients, which should be
calculated carefully through numerical calculations, i.e., 3-D Finite
Element Method (FEM). Two dif- ferent simulation models were constructed
to test the hypothesis. Moreover, rail currents, breech, and muzzle
voltages are measured to investigate electromagnetic calculations.
Results showed a good agreement with experiments where the bus structure
was modeled explicitly. That aspect showed that the bus structure should
be well-examined when multiple PPS are connected.