Affiliations: [a] School of Electrical and Information Engineering, Jiangsu University, Zhenjiang, Jiangsu, China | [b] Automotive Engineering Research Institute, Jiangsu University, Zhenjiang, Jiangsu, China
Correspondence:
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Corresponding author: Xiaodong Sun, Automotive Engineering Research Institute, Jiangsu University, Zhenjiang 212013, Jiangsu, China. E-mail: xdsun@ujs.edu.cn
Abstract: The traditional displacement sensors used in the bearingless induction motors (BIM) have many disadvantages, such as high cost, poor temperature stability, low conversion efficiency and complex motor operation. To improve these disadvantages, the detailed study on the novel displacement sensorless control based on the model reference adaptive system (MRAS) is presented in this paper. Firstly, the principle of radial suspension force generation and the mathematical model of the BIM are introduced. Secondly, the basic structure of the proposed MRAS is constructed and the stability is verified by the Popov’s integral inequality. Thirdly, to improve the control accuracy and dynamic characteristics of sensorless vector control system, a method of directly controlling rotor eccentric displacement by using suspension force compensation is proposed. Finally, the feasibility and accuracy of the proposed method have been verified by the simulation and experimental results. According to the results obtained, the radial displacement of the rotor can be accurately estimated, and the rotor displacement sensorless control of the BIM based on MRAS is achieved.
Keywords: Bearingless induction motor, model reference adaptive system, rotor displacement sensorless control, direct suspension force control
