The inherent unbalance in a 3-phase linear induction motor (l.i.m.) operating under a voltage-fed mode is accentuated by end effects at high speeds. The voltage-fed operation is analysed by identifying the slip-dependent inductance coefficients corresponding to the positive- and negative-sequence components, and taking into account the stator resistance and leakage reactances. The approach takes c...

A frequency-domain approach for the transient modelling of a voltage-fed, double-sided sheet-secondary-type linear induction motor (l.i.m.) is discussed. The problem of sudden reconnection of the l.i.m. in the motoring and braking modes at different operating speeds is analysed using discrete Fourier transforms. Attention is focused on the transient currents and thrust pulsations immediately following the switching action. The computational considerations for efficient calculation of the time response of the machine are discussed. Experimental results pertaining to the switching-in of a 2.5 kW l.i.m. from a 3-phase supply are presented, and compared with the predicted theoretical results.