A new approach to vector control for a linear induction motor considering end effects

An equivalent circuit model in the rotor flux oriented frame is developed for the vector control of a linear induction motor (LIM) by adding the so called "end effect" to the rotary induction motor (RIM) model. We describe the effects of the end effect by introducing speed dependent scale factors to the magnetizing inductance and series resistance in the d-axis equivalent circuit. Torque and flux equations are correspondingly modified. With the vector control scheme based on the proposed equivalent circuit, one can resolve the thrust attenuation problem in a high speed. We have demonstrated through experiments the improvements achieved by the proposed scheme.