A Novel Tubular Switched Reluctance Linear Machine Shielding From Longitudinal End Magnetic Effect

Traditional linear machines are under great influence of longitudinal end effect because of their finite stacking lengths in transverse and longitudinal directions. Longitudinal end effect causes imbalance of phase performance so that linear machine's force fluctuation is aggravated. The negative impact of longitudinal end effect on a flat type switched reluctance linear machine (SRLM) is verified in this paper. In order to avoid this problem, a novel tubular switched reluctance linear machine (TSRLM) is proposed, which can shield from unexpected impact of end effect. In structure, there is no transverse cut in tubular linear machines, so tubular linear machines can evade the influence of the transverse end effect. The equivalent magnetic circuit of this TSRLM is analyzed in this paper, which proves that the TSRLM is also not influenced by longitudinal end effect. A prototype is manufactured, and its corresponding hardware platform is established. A series of simulations and experiments verify that there is no deviation performance among phases in the proposed TSRLM. Accordingly, the traditional longitudinal end effect in linear machines caused by longitudinal cuts can be thoroughly evaded in proposed TSRLM.