Design And Analysis Of Double-Sided Permanent Magnet Linear Motor With Phase-Group Concentrated-Coil

Permanent magnet linear motors have important applications in high-speed maglev trains,CNC servo systems,cordless elevators,and other fields,and have attracted widespread attention in recent years.This paper proposes a new type of double-sided permanent magnet linear motor with phase-group concentrated-coil.The primary adopts a modular structure,which continues the traditional permanent magnet linear motor with high power density,rapid response,and high power factor.At the same time,it has high flexibility,It has the advantages of scalability,strong fault tolerance,and strong versatility.It is suitable for the fields of flexible transmission systems with short and medium strokes.This article first proposes a new type of double-sided permanent magnet linear motor(DS-PMLM)using phase-group concentrated-coils,expounds the design principle of the motor,and deeply studies the working principle and thrust generation of the motor mechanism.Based on the design principle,the novel DS-PMLM with different pole-slot coordination and different winding methods was expanded,and the optimal motor structure was obtained.After comparing with the traditional surface-mounted bilateral permanent magnet synchronous linear motor,the results show that the proposed motor model has a large thrust density,small thrust fluctuations,high efficiency,and the best comprehensive electromagnetic performance of the motor.Then,because of the phase difference problem of the bilateral winding back EMF caused by the bilateral dislocation structure,adjust the phase group concentrated unit coil or the concentrated winding coil polarity on the lower primary and change the connection mode to make the lower primary winding back EMF.It is in phase with the back EMF of the upper primary winding,and when running in series,the sine of the back EMF can be enhanced,and the complexity of the control system can be reduced at the same time.Secondly,deeply study the influence of bilateral dislocation structure on detent force and electromagnetic thrust,theoretically explain the mechanism of bilateral dislocation structure to suppress cogging force and end force,and then isolate the coupling cogging force and coupling end force by double primary coupling.The end force is verified by the finite element method,and its influencing factors are analyzed.At the same time,a mathematical model based on the principle of double dq transformation is established to establish the electromagnetic thrust,and the mechanism of the bilateral dislocation structure to enhance the electromagnetic thrust is revealed in principle.Thirdly,based on the previous analysis of the air gap magnetic field,the unilateral primary normal cogging force fluctuation expression is derived using the Maxwell tensor method and the integral method,and the influence factors of each harmonic of the normal cogging force fluctuation are studied.The finite element method is used to analyze the influence law of the end breaking effect and the end additional groove on the fluctuation component of the primary normal force,and explore the influence law of the constant component of the synthetic normal force and the fluctuation when the two sides interact.Analyze the influence of the secondary eccentricity on the motor air gap flux density and the primary synthetic normal force.Finally,based on the previous analysis,the optimal design parameters of the motor cogging and end are determined,and the influence of these parameters on the performance of the motor is analyzed by the parameter sweep method.After that,the thrust fluctuation and the normal force change are determined as the optimization goals,and the genetic algorithm is used to optimize the motor with multiple goals,and the design parameters of the motor with the best comprehensive performance are obtained.