Influence of the Air-gap Changes on the Performance of Linear Induction Motor

The transient characteristic of single-sided linear induction motor (LIM) was simulated and computed using the electromagnetic field finite element analysis software Ansoft. The change of the thrust, the primary current and the air-gap's magnetic field of linear induction motor was analyzed under the different air-gap's size condition. The analysis result shows that, with the growth of air gap, the motor thrust reduces but the primary current increases, and the distribution of motor air-gap magnetic field is uneven due to the existence of end effects. Finally a comparison is made between the simulation result and the experiment result, which indicates the correctness of simulated model, thus it can provide important basis for the manufacture, optimized design and control of LIM which is used in subways.