Research On Sliding Mode Robust Control Of Suspension System And Speed Sensorless For Bearingless Induction Motors

As a new type of special motor,the bearingless induction motor(BIM),with simple and solid structure,no bearing friction,is easily to high speed and ultra high speed operation.So,it has great application potential in the field of manufacturing,new energy,microelectronics,biomedicine,and other high-tech fields.Then,due to the distribution of the BIM internal windings,the BIM has a complex electromagnetic relationship.Its rotational speed,electromagnetic torque and radial suspension force and radial suspension force have a coupling relationship.Moreover,two power circuits are required to drive and control in the practical application of the BIM,which will improve the design difficulty and cost of the BIM control system.Therefore,it is the core technology that achieving the BIM decoupling control and reducing the BIM usage cost to ensure the BIM reliable operation and industrial application.Supported by the National Natural Science Foundation of China(61174055)and the Key Research and Development Project of Jiangsu Province(BE2016150),theoretical and experimental research on the decoupling control technology and speed sensorless technology around two degrees of freedom BIM are developed.In view of the needs of the BIM suspension system control,a sliding mode robust decoupling control strategy of the BIM suspension system based on HJI theory is proposed in this paper.First of all,When the suspension system is modeled,a new suspension system motion model,that the uncertainty of the system and the external disturbance are considered,is established.Then,the traditional PID controller.is replaced by the designed sliding mode robust controller,which is not dependent on the BIM precise mathematical model and neglects the influence of the change of the parameters of the motor.The robust condition of the HJI inequality is satisfied by designing a suitable sliding mode control law to ensure the stability of the control system.Finally,the simulation results show that this method realizes dynamic decoupling control of the BIM suspension system and improves the stability and disturbance rejection performance of the system.In addition,in order to accurately estimate the speed of the BIM in real time and realize the speed sensorless operation of the BIM,a new method of rotor flux observation of improved voltage model based on ISOGI-FLL was proposed,which adopts second-order generalized integrator with frequency locked loop to replace the original pure integrator.Meanwhile,the sampling current is processed by filtering,amplitude and phase compensation.The simulation experiment shows that the method has better observation effect compared with the traditional method of voltage model observation.At the same time,the speed estimation algorithm improves the accuracy of speed estimation,reduces the error of speed estimation and has strong robustness.At last,the experimental platform based on dSPACE1005 system is designed for the BIM,and then the design principle of hardware circuit,software development process and operation process of the experimental platform are introduced.Finally,the experimental verification is completed.