Novel Zero-Sequence Current Excited Double-Sided Vernier Reluctance Linear Machine With High-Order-Harmonic Toroidal Winding

Double-sided Vernier reluctance linear machine (DS-VRLM) is very suitable for long stroke applications, taking advantages of magnet-free design, eliminated magnetic pull and high thrust force density. Aiming to eliminate extra DC coils in DS-VRLM, and further boost the thrust force density of it, a novel non-overlapped double-layer integrated toroidal winding design excited by zero-sequence current is proposed in this paper. The key to achieving this is to utilize artificial arrangement of integrated toroidal winding to generate spatial high-order harmonic of magnetic field for higher pole pair number and gear ratio to acquire enhanced thrust density. Meanwhile, thanks to the toroidal winding configuration, the integrated toroidal winding could make full use of working harmonics, contributing to enhanced winding factor.