A Study on the Type of Primacy Winding Connection in Short Secondary Member Linear induction Motors Driven by Voltage Source

Abstract

This paper is concerned with the type of connection in the primary windings in short secondary member linear induction motors (LIMs). Differently from rotating motors, the LIM does not have periodical magnetic circuits, and the characteristics are much different between parallel-connected and series-connected primary windings. In this paper, using the two-dimensional finite element (FE) analysis considering practical conditions such as, constant voltage power sources, series impedance in the primary circuits, we investigate differences of characteristics for each connection. The results are also compared with experiments to confirm the validity of the analysis, resulting follows; (1) For the double-sided LIM, the performance of the parallel-connected machine is superior to that of the series-connected, because it yields an ideal distribution of the primary current such that the linkage flux increases and the leakage flux decreases. (2) For the single-sided LIM, the adoption of series connection, which is not done in ordinary design, improves the performance, because it yields an ideal distribution of the primary voltage such that the linkage flux increases. (3) We propose a novel block feeding method for use in the single sided LIM.