The Commutation And Experiment Investigation Of Coil Electromagnetic Launcher

Electromagnetic launcher(EML) is a new device pushing objects by electromagnetic force. It has a lot of advantages, such as high muzzle velocity, high efficiency, easy to control, various structures and so on, so it is concerned by strategists around the world. It has entered the practical stage in some countries.There are two basic types of EML, one is the rail EML and the other is the coil EML. Compared with the rail EML, the coil EML is more complex and is relatively more slowly developed. But the coil EML is more efficient, easily repaired, and it is suit for launching massive projectile, so it has great potential for development.In this paper, based on the theory of coil EML and MAXWELL Software, the basic model of the helical coil EML during the launching process was established; the commutation process of coil EML was established in PSPICE and the transformation and diversion of energy, the effect of back voltage and the power source during commutating process of the coil EML were analyzed; the effect of the permeability and conductivity of the coil EML’s shielding material on the launch performance were investigated; the simulation data was validated by the coil EML experiment which optimized the configuration of the coil EML and enhanced the efficiency of the coil EML.The conclusions are as follows:The commutation process is mainly decided by the flux coupling mechanism and the energy transformation between the various components is completed by the magnetic coupling between the components. The power system does little effect on the energy conversion. The arc discharge between the projectile brushes and drive coil is the main reason for energy discharge. Through the rational use of brush material and optimal design of brush shape, the arc discharge can be effectively prevented and the efficiency of coil EML can be improved. The program of zero exit current mode of coil EML is proposed after analyzing the effect of back electromotive force induced by the moving projectile. Given the fixed current of the driving coil, the electromagnetic radiation was effectively reduced and the muzzle velocity of the projectile increases by increasing the thickness of the shield. Using the solid shield was better than using the multi-layer shield.