Design And Analysis Of A Novel Double-stator Permanent Magnet Machine

The novel double-stator permanent magnet (PM) machine is compacted with fractional slot concentrated winding and double-stator PM machine. Thus, not only does it inherit the merits of the fractional slot concentrated winding, short terminal length, saving the copper using, reduce the copper loss, increase the efficiency, the small cogging torque, but also inherit the merits of the double-stator PM machine, high torque output, high utilization rate of the space and material, high torque density and low initial, those make it as the low initial and high torque machine with low cogging torque. But the double-stator PM machine has two stators, the magnetic field of the inner and outer stator is coupled together, the armature reaction is more complex than the other common machines, then it needs the precise magnetic field calculation to the better analysis. This thesis mainly focus on the design of the novel double-stator PM machine and the analysis of the machine with advanced magnetic field calculation method.Firstly, researching the rule of the novel fractional slot concentrated winding and EMF, the influence of the harmonic winding factors to the EMF is analyzed. Then, analyzing the MMF of the novel fractional slot concentrated winding, explaining the theory of the fractional slot concentrated winding machine. On the base of it, the coaxial radial double-stator structure is adopted, and two machines are made, one is a BLDCM, the other is a generator. From the 2D static magnetic field analysis, the properties of the double-stator are obtained, and they are confirmed by the test.Secondly, the magnetic field of the inner stator and outer stator in the double-stator PM machine are influenced each other. When the machine worked as a motor with non-sine wave power supply, if you want to analyze the dynamic properties of the double-stator PM machine, the field-circuit-coupled FEM will be needed, it can think about the iron saturation, tooth-slot influence, armature reaction, non-sine wave power supply, etc. This thesis puts electric potential center of the Y-connection circuit equations with FEM equations together, then creates the complete field-circuit-coupled FEM mathematics model of the double-stator PM motor. Then the motion of the FEM grid model of the double-stator PM motor is resolved, it establishes the base for the more complex control strategy in the FEM simulation. With the strategy of current and location close-loop at the same time, the BLDC and BLAC control methods are realized in the double-stator PM motor. Just because the mutual inductance of the phases is very small with the new novel fractional slot concentrated winding, this thesis put the scalar control method on the double-stator PM motor in the field-circuit-coupled FEM, and it does well. The thesis still creates the field-circuit-coupled FEM equations of the constant speed generator, and puts it simulate the double-stator PM generator.Thirdly, the surface PM faces the airgap magnetic field directly, so the magnetic field in the PM will be influenced easily, thus the eddy current will be produced. This thesis puts forward the new model of the PM eddy current loss calculation, which avoids the hypothesis of unlimited length of the eddy current region; this model is more closer to the real status. By compacting it to the field-circuit-coupled FEM, the whole system field-circuit-coupled FEM mathematics model is created, the computer program is made, which is used to analyze the double-stator PM machine, then the tests indicate that the simulation result agrees with the test results than without PM eddy current model.