Performance analysis of linear induction motor for electromagnetic catapult

Based on the operating principle of linear induction motor(LIM), this paper analyses the performance of the LIM, which is constructed on long sectioned transverse flux stator and short flat aluminum mover. Firstly, the basic requirement and working mode of this special type of catapult are presented, then the optimal design methods of the LIM are analyzed, some important parameters which would affect the work performances, such as the slot width, pole pairs of the stator and the thickness of the mover are discussed detailedly. Finally, the optimal system design is calculated and the performance is discussed by the T-type equivalent circuit considering the cover and uncover section. The phase current, phase voltage and power capacity, and the height is 11359A, 3000V, 409MVA and 1.73m respectively. The launch profile is also derived by the model. To verify the Electro-Magnetic Compatibility(EMC) of the LIM, 3-D magnetic model is built and the results show that the magnetic fields fall to the Earth's ambient level at 1 to 2m above the stator, which could not bring low frequency EMI to the entironment.