Study On Speed Sensorless Control Of Bearingless Induction Motor

Bearingless induction motor is a new type of motor that integrates the function ofmotor and magnetic bearing. Compared with magnetic bearing motor, bearinglessinduction motor has advantages, such as high space utilization, high electromagneticefficiency and simple structure. Consequently, bearingless induction motor becomes ahot research topic for many experts and scholars at home and abroad. However, whenbearingless induction motor works at high-speed or ultra-high-speed operation status,the photoelectric encoder speed sensor cannot meet the demand of long-term highprecision tacho. How to get the speed signal becomes a critical issue of puttingbearingless induction motor into practice. Therefore, the research on bearinglessinduction motor speed sensorless control has important practical significance.Based on analysis of the operating principle of bearingless motor, the paper buildmathematical models of the bearingless induction motor, and do research on rotor fieldoriented vector control system. Then, do a systematic research on rotor flux estimationand speed estimation based model reference adaptive in the motor running. Aiming atthe rotor flux estimate of bearingless induction motor, proposes a novel flux estimatorthat does not contain the parameters of the stator and rotor resistance, and found itsmathematical model. Improve the reference model of model reference adaptive system,and establish the mathematical model and control system structure of improvedbearingless induction motor speed sensorless vector control system. At the same time,do the simulation and verification of the two mathematical models by Matlab/Simulink.Simulation results show that: the estimated rotor flux amplitude and phase angle errorbased on the novel flux estimator is approximate zero. The speed estimation error andsteady-state error is smaller, and the estimated speed is much smoother.In the paper, we design the digital control system of the bearingless inductionmotor based on TMS320F2812DSP, and show the main program and flow diagram ofthis control system.