Double-Sided Single-Set Winding Coordinated Active Levitation Control of Linear Permanent Magnet Motor Considering Mover Air-Gap Offset

This article proposes an active levitation control method with double-sided single-phase winding coordination for long primary permanent magnet linear motors. Unlike traditional two windings levitation control methods with thrust and levitation windings, respectively, this approach only adopts one set of windings to realize the normal force and thrust decoupling regulations between each stator and mover simultaneously by removing the additional levitation windings. The electromagnetic thrust and normal force are theoretically analyzed and an accurate mathematical model containing the relationship between the air gap and the electromagnetic force is established. The decoupling relationship between the electromagnetic force and the current under the dq frame is determined. Based on this analysis, two sets of the double-sided single-set winding are driven independently, and the electromagnetic thrust and normal force of the mover are regulated coordinately to achieve the air-gap offset active levitation control. An experimental platform is constructed to assess the feasibility of the proposed active levitation control and evaluate the effectiveness of the designed control system.