Thrust Ripple Reduction Research Based On V-coil Permanent Magnet Synchronous Linear Motor

Double secondary air-core permanent magnet synchronous linear motor(PMSLM)is widely used in laser engraving machine and the field of high-precision machines due to many advantages such as high thrust density,low loss,fast response and simple structure,and is not affected by cogging force and iron core breaking,they application prospect are broad However,due to the existence of thrust ripple,this type of linear motor will also cause some problems such as noise and oscillation,which seriously affect those operating characteristics and reduce machining accuracy.Therefore,it is of great theoretical and practical significance to carry out research on the suppression of thrust ripple of PMSLMIn this work,the V-coil PMSLM is taken as the research object.The motor is designed according to the traditional rectangular coil motor structure and its structural parameters are optimized to achieve the effect of suppressing thrust ripple.According to topological structure,operate mode and analysis results of linear motors,a V-coil PMSLM is designed and its finite element simulation model is established.Based on the analytical model results,the structural parameters are selected,and the finite element simulation provides data,and the SVM method is used to establish an accurate calculation model.To "maintain average force and obtain minimal thrust ripple",the optimization algorithm is used to optimize the linear motor structure to align the linear motor structure to the best.The linear motor prototype test platform is bulit for experiment,and the prototype is tested under different working conditions.The experimental results verified the effectiveness of the designed V-coil PMSLM in suppressing thrust ripple.The following aspects of the designed motor in this work are studied:(1)Analyze the structural composition and characteristics of V-coil PMSLM and design the motor structure.This paper introduces the structural components of linear motors and the evolution process of V-coil.The equivalent magnetization method is used to establish an air-gap magnetic field analysis model of rectangular coil PMSLM.The V-coil structure is based on the changes of rectangular coil structure and the changes to the analytical form Analyze the air-gap magnetic field,induced electromotive force,force,and thrust ripple of the V-coil PMSLM,and more intuitively show the influence of changes in various structural parameters on force and thrust ripple.(2)The change of the structural parameters of the linear motor will affect the thrust,thrust ripple and other results to varying degrees.The selection of parameters that have a large impact on the performance of the linear motor can provide a basis for subsequent parameter optimization.The influences of structural parameters such as coil angle,coil end size,magnet width and height,and pole pitch on the thrust and thrust ripple of V-coil PMSLM are analyzed The optimizable ranges of parameters are given.These parameters are treated as optimization basis to prepare for future optimization studies.(3)The finite element analysis method is used to establish an accurate model of the V-coil PMSLM.The linear motor model is subjected to finite element calculations,and the relevant structural parameters are used as design variables.An accurate calculation model is established using the support vector machine(SVM)method to fit the precise input and output relationship of the linear motor.Aiming at "the force is not weakened and the thrust ripple is minimal ",the ant colony algorithm is used to optimize and iterate the relevant structural parameters of the V-coil PMSLM to obtain an optimal set of structural parameters to achieve the goal of the smallest thrust ripple.(4)In order to verify the effectiveness of the linear motor designed in this paper to suppress thrust ripple,an experimental prototype and a test platform were built.The prototype and the establishment of an experimental platform were used to verify the adaptability of the V-coil PMSLM at different speeds and under different load working conditions,and compared it with the rectangular coil PMSLM under the same experimental conditions.The experimental results are analyzed to verify the correctness of the V-coil PMSLM designed in this paper to suppress thrust ripple.The main innovative work of this paper is as follows:(1)A mover structure of V-coil PMSLM is designed.The designed motor can suppress the thrust ripple effectively.(2)A more complete analytical model has been established to analyze the effect of the end size and various optimization parameters on motor output performance,laying the foundation for motor modeling and optimization(3)Since the material types used to build the motor are the same as those of the comparison motor,the time cost of material selection is saved,and there is no need to rebuild the control platform,and the material cost is also saved.