Magnetic Levitation Permanent Magnet Linear Synchronous Motor Design And Control Strategy Research

Permanent magnet linear servo system cuts the mechanical transmission institutions and eliminates some adverse effects caused by the mechanical commutation institutions. This linear drive technology of permanent magnet linear synchronous motor has been widely used in the field of CNC machine, which greatly improves rapid response capability and motion precision of the feeding system. However, the friction between the mover and the static guide causes thermal deformation, especially in the low speed and nonlinear, which reduces the linear servo properties and processing precision. Therefore, how to effectively reduce or eliminate the friction caused widespread concern. This dissertation proposes a new direct maglev structure of permanent magnet linear synchronous motor to eliminate the friction between the mover and the static guide. The major research content of dissertation as follows:(1) Aim at NC machine tools friction-free feeding requirements, the dissertation proposes a kind of double windings structure of magnetic levitation permanent magnet linear synchronous motor. One is the thrust winding, which is used to generate electromagnetic thrust, the other is the levitation winding, which is used to generate magnetic levitation force.(2) The control strategy is analyzed through the establishment of motor mathematical model. The mathematical model of the motor electromagnetic thrust and levitation force will be derived by the Maxwell stress tensor method. In the control strategy of i1d=0,i2q=0, Ansoft is used for making finite element analysis of the motor electromagnetic thrust and levitation force, which permanent magnetic materials are different.(3) Designing the motor armature winding structural type and secondary structure, and researching the influence of the air gap height on levitation force and thrust. By choosing the appropriate air gap height, this motor can generate enough air-gap magnetic field to satisfy the requirements of thrust and levitation force, and levitation force of mover is uniform, which meets the high performance requirements of motor.(4) A Matlab electromagnetic calculation program is designed for a magnetic levitation permanent magnet linear synchronous motor. According to the national natural science fund projects research requirement, a magnetic levitation permanent magnet linear synchronous motor is designed, and finished its electromagnetic computing.