Tolerances in Flux Compression Generator Design: Theory

TL;DR

This paper develops formulas to evaluate how manufacturing tolerances affect the output power of flux compression generators, aiming to ensure consistent performance despite component variations.

Contribution

It introduces simple formulas to assess the impact of component tolerances on FCG output power and proposes design requirements for minimal power variation.

Findings

Formulas quantify effects of insulation thickness and explosive velocity changes.

Acceptable tolerances for third-party manufactured components are established.

Design guidelines ensure stable output power despite inductance variations.

Abstract

A flux compression generator (FCG) is a device generating a high-power electro-magnetic pulse by compressing magnetic flux with the help of explosion. The physical properties of components and materials used for FCG manufacturing and available on the market (wires, explosives, liners (armatures), etc.) might differ from those originally used for FCG design. As a result, the output parameters of the manufactured generator (e.g. maximum output power) could deviate from the pre-calculated values. Simple formulas are derived to enable evaluation of change in output power delivered to a purely inductive load from a helical flux compression generator in case when the wire insulation thickness or the detonation velocity of explosive or load inductance $L_l$ are changed. The obtained formulas establish acceptable tolerances for FCG components produced by a third-party manufacturer. Design requirement is proposed to ensure minimal dependence of the output power delivered to the purely inductive load when its inductance is varied a bit. The proposed approach implies approximate equality of load inductance and the residual FCG inductance at the instant, when the output power is maximal.