Research Of Digital Control System Of Bearingless Slice Motors On DSP28335

The bearingless slice motor (BSM) is a new type of magnetic suspension motor combining the driving and self-suspension, which can not only produce the torque for load driving, but also produce the magnetic levitation force for realizing no mechanical friction rotation. For its simple structure hermetical, high ratio of axial utilization, low cost, the BSM has unique application advantages in the fields of ultra-pure driving, such as medical equipment, bio-pharmaceuticals, chemical industry, nuclear waste material, etc.This dissertation focused mainly on the digital control system design and design of BSM. A three-dimensional model was established, the passive suspension characteristics and dynamic characteristics of rotor .were analysed and digital control system based on TMS320F28335 was designed. Matlab system was introduced to support development of DSP software. The algorithm model of control systems was established with Simulink, and Simulation result showed that the algorithm was valid. The experimental results of a bearingless slice motor indicated that the rotor can be suspended and rotated successfully.Firstly, the basic principles of the BSM were discussed in detail. The finite element analysis (FEA) software, ANSYS Workbench, was adopted to establish a three-dimensional model of BSM and their computation accuracy was verified by FEA. The impact of the coefficient on the radial force and torque was analyzed deeply. On this basis , the rotor dynamic characteristics of disturbances in the axial and reverse direction were discussed for the optimal design.Secondly, the speed of operation.requirement to control unit is high, thus digital control system based on TMS320F28335 was designed. TMS320F28335 of TI coporation is contributed to digital control of the motor, its calculating speed is so fast that it can control current in real-time. In the hardware, it fully utilizes the advantage of chip that are abundant interface and fast speed so as to realize the control of the system.Thirdly, develop DSP using Matlab software system. The algorithm model of the control system was built and the algorithm simulation and the DSP executable code generation were integrated,thus the efficiency of software development can be raised. A series of problems caused by coding can be avoided. At the same time, a number of complex algorithms can also be easily set up.Finally, the experiment of BSM was achieved , the theoretical analysis and digital simulation as well as system software and hardware design is verified.