Research Of Design Method Of Field Modulated Permanent Magnetic Gear Based On Magnetic Network Method

Field Modulated Permanent Magnetic Gear(FMPMG) has extensive application prospects in the fields of wind power generation system, hydro power generation system, electric locomotive and electric ship propulsion system for its high utilization rate of the permanent magnet and high torque density. The finite element method(FEM) is mostly used in the magnetic field analysis of FMPMG until now. Despite high calculation accuracy, its calculation speed is slow, and it is unable to reflect the physical relationship between the electromagnetic performance and design parameters distinctly. So FEM is not suitable for primary design. To this end, this paper proposes the magnetic network method in FMPMG study, and builds the magnetic network model. Specifically, the following ones are included in the main work:1. The magnetic network model of FMPMG is built. According to the magnetic network theory, the calculation methods of the equivalent magnetic potential and the equivalent magnetic resistance of each part of FMPMG are presented, and base on the methods above, the physical model is established. Referring to the processing method of multi-port network in electric network, the mathematic model of FMPMG is established, and the solving method of the mathematic model is presented as well.2. The magnetic network model of FMPMG is realized in the parametric programming form for the first time, which leads to the advantage that the structure parameters of FMPMG can be modified directly, and the unit of the magnetic network model can be adjusted by modifying the simulation parameters, which lays the foundation of the FMPMG analysis.3. The program of the two-dimensional magnetic network model of FMPMG is compiled based on the calculation of the scalar magnetic potential and magnetic flux, and it is utilized in field modulation principles and static torque characteristics study. Through the comparisons of results calculated by magnetic network and FEM respectively, the results show that the calculation precision of the magnetic network model is slightly lower than the FEM model, but obviously less calculation magnetic network model demands can save calculation time effectively.4. The study in torque transmission capacity of FMPMG relies on magnetic network model is developed in three aspects: permanent magnet, air gap and ferromagnetic pole-pieces. Specifically, the influence of structure parameters on maximum static torque and torque density is analyzed, which points out the selection scheme of permanent magnet pole pairs in inner and outer rotor, and the design criteria of various parameter.