Abstract
Summary: The finite length of primary iron of linear induction motor (abbr., LIM) causes the end effect which induces unbalanced distribution of magnetic flux density in the gap varying with the velocity of secondary conductor. This fact also unbalances input currents at 3-phase terminals of LIM.
In this paper, the authors propose an analytical method for LIM by using a 3-phase equivalent circuit instead of by using a usual single-phase one which does not represent the characteristics of unbalanced 3-phase LIM sufficiently. The estimation of all the parameter-values of the 3-phase equivalent circuit under starting condition is made by phase voltages, line currents and magnetic fluxes measured at no-load test as well as at load test. It is shown that a starting thrust calculated by using obtained parameter-values is in good agreement with the measured one. Differently from a usual LIM, the primary core of tested LIM is constructed by oriented cores in order to increase degree-of-freedom of the core configuration and to decrease the slot leakage flux.
