Design of a Compact, Robust High-Current Inductor for Pulsed Power Applications

This article describes a high-current, pulse power inductor design to achieve compactness, robustness, and enhanced energy density. Conventional pulse power inductor designs focus on containing the strong expansive Lorentz forces on the inductor coil using bulky external housing. The novelty of the present design is the use of a high-conductivity metallic enclosure placed coaxially around the inductor coil which modifies the magnetic field distribution in such a way that the force experienced by the inductor coil is compressive, rather than expansive. Hence, the Lorentz forces on the inductor coil are contained using a strong inner coil former used for holding the coil, thus eliminating the need for a strong external housing. This leads to a more compact inductor design. This inductor design is studied extensively using COMSOL Multiphysics 5.3 and Opera 18R2 for validation of design concept. Based on these simulations, inductors with inductance of
$2~\mu \text{H}$
and energy density of 5 kJ/l are fabricated and tested successfully on an experimental setup to get a pulsed current of magnitude 250 kA and rise time 82
$\mu \text{s}$
with two such inductors connected in parallel as load. Based on the experimental experience and confidence gained on these inductors, a design concept of more compact inductor has also been proposed.