Design and Analysis of a Novel Transverse-Flux Tubular Linear Switched Reluctance Machine for Minimizing Force Ripple

This article proposes a novel transverse-flux tubular linear switched reluctance (TF-TLSR) machine for long-stroke applications, in which the armature windings are placed on the short primary, while the long secondary is made of only low-cost iron ring. The key for the proposed machine is to innovatively introduce the complementary tooth structure into the primary salient-pole design and equip the complementary machine unit configuration in the primary construction for the purpose of minimizing the force ripple. The principle of force ripple reduction by using these complementary structure configurations is illustrated in depth. The analytical calculations of the winding inductance and thrust force of the proposed machine are developed with the air-gap magnetic path modeling. By using the 3-D finite element analysis (3-D-FEA), the sensitivity study of two key structural parameters on the force characteristics is also carried out, based on which a satisfactory TF-TLSR machine is finally determined. Consequently, a prototype is fabricated for experimentation testing, and the FEA and experimental results are comparatively demonstrated, which verifies the validity of the design ideas of using a complementary concept for minimizing force ripple in the proposed machine.