Optimization analysis study of a multi-stage SICG based on OED

Abstract

This paper analyzes the influences of the factors in a capacitor-driven multi-stage synchronous induction coilgun (SICG) and optimal combination of the design parameters based on orthogonal experiment design (OED). Finite element transient solver is used to calculate the motion characteristics of a multi-stage SICG. The muzzle speed is set to be the target of the optimization. System parameters (factors), levels and orthogonal array (OA) are determined by the order. Three optimization schemes are compared, including stage-by-stage optimization, section optimization and full optimization. Optimal combination of the three-stage SICG is obtained, as well as important order of factors. It shows that a set of comparatively better parameters and relatively higher efficiency could be achieved through orthogonal optimum. Wire diameter and coil diameter are the most important factors that influence the system efficiency of the launcher. Besides them, length of coil, trigger position and number of turns have less influence for the system in the important order. Section optimization could reduce the amount of computations compared to full optimization and a set of comparatively better parameters and relatively higher efficiency could be achieved. It is suggested to optimize a multi-stage SICG. How to choose the factors from lots of parameters is according to the engineering practice. Improper choices of the value in levels may cause unable to reach an optimum. The conclusion will be useful for coilgun design.

Key design parameters and optimum method of medium- and high-velocity synchronous induction coilgun based on orthogonal experimental design

“…This conclusion is consistent with that obtained in Ref. [24], which used the OED to optimize the low-speed launch. The efficiency is lower when the capacitance is higher (which means a lower voltage).…”

“…According to Lenz's law, the interaction between the induced current and the radial magnetic wave generates electromagnetic force that accelerates the armature. [24] The load-side crowbar diode not only prevents the capacitor from damage due to voltage reversal caused by the inductive load during the pulsed power supply period but also blocks the induced current caused by the previous stator coil. [27]…”

“…[37] The range refers to the difference between the maximum and minimum of the average of the experimental indexes corresponding to each level in each column. The mathematical expression is as follows: [24]…”

“…Some researchers have used the orthogonal experimental design (OED) to seek the optimal parameter combination and they have tried to analyze the influences of various factors on the performance of the whole system, but it is indicated that these researches are only limited to the case of one or more coil-driven low-speed launcher. [22][23][24][25] In this work, we propose a combination of OED and selfconsistent control model, which is different from the lowspeed SICG that was used in previous work, to optimize the performance of medium-and high-velocity MSSICG. First, the self-consistent design model based on the current filament method (CFM) is established and its validity and flexibility are verified by the finite element method (FEM).…”