Research on Loss and Temperature Rise of Pulse Inductor for Electromagnetic Rail Launch

The copper foil pulse inductor used for electromagnetic rail launch works in instantaneous super-high current conditions, and the copper foil needs to bear high current density, which also affects the eddy current distribution in the metal shell. The loss and temperature rise generated in the copper foil and the shell affect the efficiency and operation stability of the pulse inductor, and are important performance indicators to test whether the pulse inductor can achieve rapid and continuous pulse discharge. The magneto-thermal coupling simulation model was built by the finite element method (FEM) and boundary element method (BEM), and the numerical calculation results of the loss and temperature rise of the copper foil and shell of the pulse inductor were obtained when the electromagnetic rail launched. Aiming at the problem of large shell loss, a structural optimization scheme is proposed to increase the gap between the copper foil and the shell and reduce the wall thickness of the shell. The simulation shows that after the structure is optimized, the copper foil loss slightly increases by 1.29% during a single launch, but the shell loss decreases by 21.33%, at the same time, the temperature rise of copper foil and the strength of the shell meet the safety requirements of $6\times $ consecutive launches. Finally, the accuracy of the simulation calculation model and the scheme to reduce eddy current loss of shell are verified by experimental measurement.