Analysis of Finite Width Effects of Single-sided Linear Induction Motor Using Hankel Functions

Construction of a prototype Single Sided Linear Induction Motor (SLIM) is not possible taking stator and rotor width to be infinite because the formation of stator winding is not possible without the overhang. Also the current path in the rotor sheet cannot be made of closed type until and unless rotor width is finite. This study takes into account, the finite width effects of both stator and rotor but ignores the discontinuity of the rotor in the longitudinal direction. The finite width effects in a SLIM are analyzed using special mathematical tools such as Hankel Function for faster numerical convergence. The basic difficulty in formulating such problem, based on electromagnetic field theory applications, is to calculate the induced current in the rotor sheet, which is electrically decoupled from the stator winding system. It is also known that currents in the rotor sheet are generally computed, based on the fact that current cannot escape the sheet. Therefore, the divergence of rotor current density being zero calls for introduction of a field quantity ＂Stream Function＂. The present paper uses stream function effectively for tackling the above said difficulty. The results presented in the study are compared with the values of a model with stator and rotor of finite width. Such comparison results can help a designer to decide a finalized value of stator and rotor width.