Improved loss model and loss minimization control strategy for linear induction machine

Abstract

The linear induction machine (LIM) suffers heavily from low efficiency, due to its large air-gap length and the influence of end-effects, including transversal edge-effect and longitudinal end-effect. Worse still, its efficiency usually goes down at light load for the comparative higher copper losses caused by constant excitation current. In this paper, to improve the LIM working efficiency, a novel LIM loss model is established to fully consider the influence of the end-effects, the copper and core losses. Based on the model, an improved loss minimization control (LMC) strategy is put forward. The steady-state performance of the proposed method is investigated comprehensively on one 3 kW arc induction machine (one prototype for actual LIM). Both simulations and experiments demonstrate the proposed can effectively reduce the machine losses with various speeds and loads.