Research On Hybrid Excitation And Permanent Magnet Flux Switching Double-Sided Linear Motor

With the developments of direct drive technology,linear motor has been widely used in industrial production.Compared with the rotating motor,linear motor can produce a direct thrust without the middle part of the transmission,making the whole system efficiency greatly improved.Due to its high thrust density and simple secondary structure,flux switching permanent magnet linear motor(FSPMLM)is more suitable for high-speed precision industrial production.The single-sided FSPMLM has the disadvantages of large normal force,large amount of permanent magnets and non-adjustable magnetic field.In order to solve the above problems,a novel yokeless multi-tooth flux switching double-sided linear motor(MTFSDSLM)is proposed in this paper which contains two structures,one is excited only by the permanent magnet and the other is with the hybrid excitation.The primary consists of yokeless core with multi-tooth structure,which can save the amount of permanent magnets and weaken the cogging force caused by the end effect.Besides,the normal force can be reduced to almost zero.When using the hybrid excitation design,the magnetic field of the motor is able to be flexibly adjusted which can expand the operating range.In this paper,the operating principle and mathematical model of MTFSLM are introduced.Secondly,in order to illustrate the advantage of the yokeless MTFSDSLM,the electromagnetic performance is compared with that of the normal MTFSDSLM with finite element method(FEM).The slot/pole number combination is also investigated according to the mathematical model and the conclusion of the optimal combination is drew.Then,a hybrid-excited structure is proposed based on the MTFSDSLM structure.The magnetic field regulation performance of the structure is analyzed and the key parameters of the structure are optimized.Finally,the prototype of MTFSDSLM is introduced and the possible manufacturing errors are simulated and analyzed.The actual test results of the prototype verify the correctness of the simulation analysis.