Design And Characteristics Analysis Of Permanent Magnet Linear Flux-switching Motor

Since development of the urban rail systems, the permanent magnet linear motors have got lots of researches and applications, due to its characteristics, there exist many major problems to overcome, such as high cost, the maintenance of difficulty and complex. Compared with conventional linear motor, the permanent magnet flux-switching linear motor(PMFSLM), can dispose permanent magnets and armature windings in a shorter side, greatly reducing the amount of permanent magnets or windings, reducing the cost and difficulty of maintenance, therefore permanent magnet flux-switching linear motors are more and more attentive and have broad application prospects.Firstly, the article introduces the domestic and abroad research situation of PMFSLM, and then the working principle is also mentioned. The mathematical model under ABC and dq0 coordinates are derived. Based on the theory of permanent magnet flux-switching motor(PMFS), the preliminary design of PMFSLM is carried out, obtaining main parameters, such as the tooth height and width of the primary and secondary, the width of permanent magnet, the type of windings, winding turns, etc. The model is built by FEM to simulate and analyze the impact of structural parameters on thrust. The preliminary design of mechanical structure can be obtained after checking these PMFSLM parameters. Then, analyze the different magnetic field distribution of the motor at load and no-load; draw out electrical power-to-angle curve to get the maximum thrust.Next, comprehensive assistant end teeth are used to reduce detent force. Verify that the optimized end structures can improve end effect to some extent. Comparatively analyze the thrust, thrust fluctuations, the symmetry of back EMF and the change in inductance before and after the use of assistant end teeth. Then compare the flux, back EMF and thrust trends in different air gap sizes.Finally, determine the motor’s heat, calculate the loss, thermal conductivity, heat transfer coefficient and convection coefficient of the various components, use the finite element to analyze the thermal field, to research the temperature field distribution of the motor for further design and optimization later.