Design And Analysis Of A Novel Double-stator Tubular Vernier Permanent-magnet Motor

Due to the shortage of natural heart and high heart disease mortality, now use artificial heart instead of natural heart has become the main way to save heart patients. Because artificial heart pump is the core component of the artificial heart therefore it must have stability and portability, while the electric artificial heart pump just has these advantages, so the electric artificial heart pump has the research value.This paper presents a novel double-stator tubular permanent-magnet vernier(TDS-VPM) motor used in artificial heart pumps field, and carried out research on its static and dynamic performance, build a finite element model, design and manufacture a test prototype, confirmed the outstanding performance of the TDS-VPM motor, in order to further study the TDS-VPM motor. Major efforts are as follows:1) Due to the limited space and the requirement of higher thrust density performance, a TDS-VPM motor is proposed with the improved PM structure. The windings and permanent magnets are located on the stators, and there is a mover between the two stators, which is only composed of mover core. Using this structure can effectively use the motor hollow volume, reducing the motor length, increase the thrust density and improve the heat capacity of the motor.2) Established an ax symmetric finite element model of the motor, and simplified the 3D model structure to 2D model to save the simulation time. The motor magnetic field distribution, flux linkage, back EMF, inductance, and thrust are analyzed, the results verifies the correctness of the vernier theory.3) Constructed a symmetrical model to isolate the end force and cogging force. According to which the motor topology is optimized. By staggering a quarter pitches of inner and outer mover tooth, the inside and outside cogging force can be offset. In this way the mover thrust pulsation is effectively reduced and the output performance is improved.4) A mathematical model of the motor is established and a current control when the back EMF of two phases is not 90° electrical angle is derived. Using the coupled field-circuit simulation method, the dynamic characteristics of the motor is analyzed.5) Due to silicon layers is not suitable for the tubular structure, the material properties of new soft magnetic materials used in slope Mo alloy is tested. The test showed that the magnetic permeability of new soft magnetic material is lower than the silicon material. Design and manufacture a test prototype, and the analysis results show the experimental results agree well with the simulation results, which verifies the correctness of the theory.