Efficiency Optimization And Experimental Studies On Multistage Iduction Coil Launcher

Electromagnetic launcher(EML)uses electromagnetic force to accelerate projectile to a certain velocity.This technology has several advantages,including inexpensive energy source,high muzzle speed,wide range of projectiles' mass and high energy conversion efficiency.Thus,EML technology has extensive application potential in new weapon,aircraft carrier catapult,civil transportation and other fields.Conventional EMLs can be divided into railgun,coilgun and reconnection gun,the coilgun still has certain deficiencies as a research hotspot.This article has studied and analyzed the following aspects,including turns of coil,external circuit parameters,driving coil's package shell,characteristics of interstage coupling.Finally,an experimental platform was set up to conduct an experimental study.Firstly,this dissertation establishes coil launcher's mathematical model based on the field and circuit,analysis coil launcher's electromagnetic characteristics and provide theoretical basis for next simulation and experiment.Next,a single-stage coil launcher model was established to optimize external circuit and drive coil parameters to maximize the launch efficiency of a given projectile.Then,according to the influence of the package shell on the launcher efficiency,a single coil launcher simulation model was established to analyze the influence of the shell material and the package size on the emission efficiency.The simulation results show that we can improve the emission efficiency by reduce shell conductivity,the thickness of the shell,gap between shell and driving coil and enhance shell permeability.And emission efficiency can also be improved by slotting the shell.In addition,coil launcher's characteristics of interstage coupling is affected by the armature speed and the distance between stages.Based on the analysis of the coupling effect,an optimal control strategy for the trigger position of multi-stage coil launcher is proposed,and a simulation model for a three-stage coil launcher is constructed.Simulation results surface characteristics of interstage coupling have an effect on the launch of multi-stage coil guns and optimal control strategy can indeed improve coil launcher's efficiency.Finally,a three-stage coil launcher experiment was conducted and the experiment firstly verifies that the emission efficiency is the largest when the number of turns of the driving turns of coli is 150 in the single stage emission process.The single-stage luncher is used under the conditions of 2500 V and 400?F without containment,slotted containment and unslotted containment and the armature exit speeds were 21.27 m/s,11.43 m/s,and 9.36 m/s.A three-stage coil launcher experiment was conducted,in which a three-stage coil launcher was used to supply 5000 V and 400?F capacitor banks in each stage.Before and after optimization,200 g aluminum alloy projectiles were accelerated to 72.66m/s and 85.27m/s respectively.The experimental results are applicable to the feasibility of the optimal control strategy for trigger positions of multi-level coil transmitters.