Optimization Design And Digital Control Research On Bearingless Permanent Magnet-Type Motor

A Bearingless Motor is a novel electro-magnetic machine that has the functions of the electric motor and an active magnetic bearing.Bearing windings are wound together with conventional torque windings to produce radial suspension forces in stator slot of the bearingless motors.The rotor is successfully supported by electromagnetic forces and rotates as the conventional motors.Compared to traditional permanent magnet motor,permanent magnet type bearingless motor has a serial of more advantages,such as no mechanical touch,no wear, high-speed,high-precision and long life-span.So it has potential prospect application in those special electric transmission fields of bioengineering,aviation,new energy sources, semiconductor manufacture and medicine sanitation and so on.Thus the research on permanent magnet-type bearingless motor has attached special attentions.The main works of this dissertation are as follows:Firstly,the basic configuration and function principle of permanent magnet-type bearingless motor are discussed in detail and the mathematics model of motor is deduced.Then,the theory of rotor flux orientation control is adopt to realize the independent control of circumrotate and suspend stably to the rotor as well as decoupling control between torque force and radial suspension force.Also,the decoupling control diagram of the permanent magnet-type bearingless motor is given out.Secondly,the model's design of the permanent magnet-type bearingless motor is studied. And the designs to the structure of permanent magnet-type rotor,torque winding and suspension winding are analyzed in detail.At the same time,the influences to torque performance and suspension performance because of the permanent magnet thickness are lucubrated.Based on this, the number of turns of torque winding and suspension winding,optimal suspension force,optimal output power are optimized by using ANSYS software.Furthermore,the basic work theory of the permanent magnet-type bearingless motor is testified.It educes that radial force which can suspend rotor is produced surely when torque winding and suspension winding electrified at one time.Finally,based on rotor flux orientation control of permanent magnet type bearingless motor and its mathematics model,the structure of digital control system is designed and simpled for permanent magnet type bearingless motor.Then,the hardware and software of digital control system is designed based upon TMS320LF2407 of TI Corporation.The digital control system is debugged and optimized.The experimental results of digital control system are given and the results of debugging validate that the control strategy and control system satisfies the needs of control.