Control Strategy Research On Moving-Coil Permanent Magnet Planar Motor

In consideration of Permanent Magnet Planar Motor has greater comprehensive advantages over conventional motor in terms of structural diversity,thrust density,control accuracy,low-speed performance,energy loss and so on,and therefore it has been constantly attracting the research and update of academic circles and engineering circles at home and abroad.In this thesis,Moving-coil Permanent Magnet Planar Motor is taken as the research object,and the research is mainly focus on the establishment of force model,decoupling motion control,lifting and falling motion control of the mover in the z-axis,and position sensorless motion control of the mover in the xy plane.The details are as follows:1.The basic structures of a moving-coil permanentmagnet planar motor and the mathematical model of the magnetic field of the stator Halbach permanent magnet array are introduced.Meanwhile,the force analysis mathematical model of the moving coil is deduced,and the basic equations of the motion of the Moving-coil Permanent Magnet Planar Motor are summarized.A static three-phase/moving two-phase coordinate transformation matrix of a moving-coil permanentmagnet planar motor is proposed,and a new theory of work current and decoupling current is made.Based on this concept,the electromagnetic force current distribution equation and other related transformation matrices are derived.After summarizing the mathematics,the control of the moving-coil permanent magnet planar motor was introduced into the work and decoupling fields for discussion,and the design of the voltage-mode electromagnetic force control system was performed.2.This thesis analyzed the maglev up and down moving process under the control of real-time current distribution strategy,put forward the concept of “false air gap point”,deduced the mathematical equation between the position of "false air gap point" and the desired air gap position and the time calculation integral formula that when mover moves up to desired air gap position and descends to zero altitude.The “false air gap point” has two reflections.One is that when the mover stays at the zero position,the coil is assigned a "false air gap point" constant current and the speed of the mover running to the desired air gap point is zero on the condition of the current drive.The other is when the mover floats at the desired air gap position,coil is distributed “false air gap point” constant current and the speed of mover running to zero position is zero as the result of the current drive.The control strategy makes use of the above-mentioned phenomena,and moves the mover smoothly between the zero position and the air gap point by switching the current.Simulation result shows mover running deviation and jitter are very small,which proves the validity of control strategy.3.Based on circuit energy conservation,utilizes Kalman filtering estimation algorithm to conduct state estimation for achieving mover position information to process electromagnetic force control,which produces levitation force and horizontal thrust acting on active cells to control sensorless.The strategy can constantly obtain terminal voltage and current from moving coils to export total power and get the mechanical power acting on the mover through subtracting the thermal power consumed by the moving coils.The mechanical power reacts the size of the displacement in the mover sampling interval under constant thrust control,so as to establish Kalman filtering estimation algorithm model of the position,velocity and acceleration of the mover.On this basis,taking a simulation for the thrust coming from the control algorithm and the control strategy,and the simulation result was verified that the control strategy is correct.