Section crossing drive with fuzzy-PI controller for the long stroke electromagnetic launcher

Compared to the traditional steam catapult systems, the electromagnetic launch (EML) system with the permanent magnetic linear synchronous motor (PMLSM) has the features such as high efficiency, high power density and controllability, thus PMLSM is used in the EML system. In this paper, the long primary short secondary PMLSM used in electromagnetic launch system is designed, whose winding in the primary is divided into two sections. The control system employs two inverters and two current trackers, and the latter are adopted to track the 3-phase currents in the other section when the mover is in the cross section, so as to make the magnetic traveling field excited by the two windings move forward smoothly, and the thrust stable. With regard to the system nonlinearity and model variation, the fuzzy PI regulator is designed to adjust the mover velocity. In contrast to the conventional PI regulator, the simulation results show that the thrust is stable at section transition and the velocity reaction is quick without overshoot. The scheme proposed here is validated by the simulation results.