Three-phase pole-by-pole model of a linear induction machine

This paper develops a stationary-reference-frame coupled circuit model for a 4-pole linear induction machine (l.i.m.), a model similar in nature to the abc-phase model used to predict conventional round-rotor machine behaviour. A comparison between model predictions and high-speed double-sided l.i.m. data shows that good predictions can be made using equivalent-circuit parameters calculated from machine dimensions. It is shown that the application of the (d, q) transformation slightly degrades the predictions for the machine studied, at the same time halving the computational time. The model derived requires a mathematical lengthening of the machine´s primary. It is shown that results are improved when the actual length of the primary is used to calculate coupling coefficients for the model. Since the basic abc-phase 4-pole machine model is represented by a matrix differential equation of order 15, programming and solution time are relatively short as compared to some other methods.