Drive Circuit Study of Energy Recovery for Reluctance Coil Launcher

Abstract

The reluctance coil launcher relies on the electromagnetic force generated by the magnetic field formed by the pulsed current in the drive coil to propel the ferromagnetic armature to accelerate. However, during the launching process of the reluctance coil launcher, the armature is subjected to the reverse drag force generated by the coil current after passing through the center position of the coil, which leads to a decrease in the speed of the armature and the efficiency of the launcher. In order to cut off the coil current at the right time, reduce the drag force effect on the armature, and recover the excess energy, this article proposes two circuit topologies for recovering the residual energy, in which the Type 1 energy recovery circuit can recover the energy of the residual current into the capacitor to save power for the next launch and the Type 2 energy recovery circuit improved based on the Type 1 circuit structure can realize that the energy recovered from the previous stage can be used for discharging the subsequent coils. Based on the simulation results, experiments of a two-stage reluctance coil launcher are carried out to validate the feasibility of the energy recovery circuit topologies. The results show that the Type 1 energy recovery circuit increases the efficiency of the original launcher from 7.16% to 10.36% and can recover 10 J of energy to the capacitors. The Type 2 energy recovery circuit has an efficiency of 10.49% and recovers 36.524 J and the Type 2 energy recovery circuit therein, based on the recovery of excess energy, uses that portion of the energy in the next stage of the launch process instead of retaining it until the next launch process, further improving the launch efficiency. The above results provide a new reference for improving the efficiency of the reluctance coil launcher using the circuit topology approach.