Modeling And Drive Control Of Y-type Permanent Magnet Planar Motor

Permanent magnet synchronous planar motor is a new type of motor that can use electromagnetic energy to make motor move.Compared with the traditional planar motion mechanism,it has the advantages of simple structure,stable output,high motion accuracy and low loss.It has a wide range of applications in integrated circuit design,precision manufacturing and other industries,and it has become a popular direction for research in various countries this year.The typical application of planar motor is lithography machine.In order to achieve the independent design and development of high-end lithography machine in China,the research of plane motor becomes particularly important.In this paper,the mechanical structure,working principle,electromagnetic distribution,drive design and overall control of the permanent magnet planar motor will be introduced.Firstly,this paper introduces the whole structure of the plane motor,including the moving platform,the stator platform,the driving structure and the coil winding,and analyzes the working principle of the plane motor.The plane motor uses a linear Halbach permanent magnet array to provide the magnetic field,the distribution of the magnetic field generated by the permanent magnet array is analyzed by finite element simulation,and the influence of permutation of permanent magnet and air gap height on the distribution of magnetic field is discussed.Secondly,the physical model of Halbach permanent magnet array is set up,and its spatial magnetic field distribution formula is deduced by the equivalent current method,and the electromagnetic thrust and coil back electromotive force are calculated according to the spatial magnetic field.Then,the voltage and thrust balance formula under the transient and steady state are deduced.The spatial magnetic field distribution generated by the permanent magnet array is viewed through three-dimensional finite element simulation,the electromagnetic thrust of the energized winding at different positions is simulated,and the positional relationship between the horizontal thrust and the vertical thrust is obtained.Thirdly,according to the structure of the plane motor drive unit,the drive circuit of the plane motor is designed.In order to achieve higher positioning accuracy,the switching frequency of the drive circuit is larger,which brings a lot of high-frequency harmonics.The RC low-pass filter is used to filter it,A current switching method based on time weight coefficient,compared with direct switching method,greatly reduces the coil current fluctuation caused by switching.Finally,according to the overall control model of the plane motor,the distribution mode of the electromagnetic thrust and the coil current of the plane motor is decoupled.The control process from the position of the plane motor to the thrust and then to the coil winding current is analyzed,and the dynamic model of the plane motor is established to simulate the motion of each degree of freedom.