Analysis on performance of linear induction motor basing on winding function method

Winding function method is adopted in this paper basing on air-gap magnetic flux density equations, and a new equivalent circuit is presented so as to analyze single linear induction motor (SLIM) applied in linear metro. Steady and dynamic performances of SLIM can be predicted by this circuit considering end effects, half filled slots, saturated iron and skin effect. To begin with, dynamic situation under constant current constant frequency and several stable cases like constant current constant frequency or variable frequencies, constant voltage constant frequency or variable frequencies are presented in detail. Then, dynamic characteristics of SLIM under slip frequency control in both constant current and voltage drive regions are investigated. Furthermore, comparisons between conclusions on phase current, thrust, efficiency of high power SLIM and experimental results are made. The results indicate that winding function method is definitely reasonable to describe performance of SLIM, especially its end effects. It can be used in the design and performance prediction of SLIM.