Inductance Computation Consideration of Induction Coil Launcher

Inductance computation is an important issue for the design of the induction coil launcher (ICL). The self-inductance of the driving coil and the system equivalent inductance of ICL are investigated in the paper. Computation equations are presented. Both theoretical computation method and simulative computation method are employed for the inductance computation. Theoretical computation methods consider the influence of the per turn coil´s distribution, and the simulative method doesn´t consider the influence of per turn coil´s distribution. Under the condition of static magnetic field, the deviation between the theoretical computation result (L=150.46 mu H) and the simulative result (L=147.22 mu H) is low, which shows that per turn coil´s distribution has little influence on the self-inductance of the driving coil. The theoretical computation method for the system equivalent inductance is also presented. As for the system equivalent inductance, the simulative result is 83.69 mu H, and the theoretical result is 99.396 mu H. These mean that per turn coil´s distribution has large influence on the system equivalent inductance under the condition of eddy current. The system equivalent inductance is much lower than the self- inductance of the driving coil. Therefore the system equivalent inductance should be employed to evaluate the factual working parameters of ICL In addition, computation formula for the mutual inductance between the driving coil and the armature are given out.