Numerical Treatment of Transverse Edge Effects in Linear Induction Motors

A 3-dimensional-field analysis is presented for the treatment of finite-width effects in linear induction motors (LIM). Account is taken of the effects of stator fringing and rotor-end-portion leakage. The model allows for a finite iron height and width, an arbitrary lateral secondary displacement, and the secondary iron width different from the primary iron width. The method used involves numerical solution of difference equations for the magnetic vector potential as well as a scalar potential. The performance such as thrust, real and reactive power are obtained from the vector potential, and the induced primary voltage. An equivalent circuit with a secondary leakage reactance and modified finite-width correction factors is proposed.