Sensorless control of bearingless induction motor based on back electromotive force method with ESO compensation

In order to realise stable suspension and accurate sensorless position control of the Bearingless Induction Motor (BIM) under speed transients, the paper proposes a novel sensorless position control strategy that integrates Active Disturbance Rejection Control (ADRC) with the Back Electromotive Force (BEMF) method. Based on the conventional BEMF observer, an Extended State Observer (ESO) is introduced to estimate and compensate for disturbances during flux observation. This method effectively reduces inherent issues such as integral drift and model uncertainties in traditional methods, thereby laying a solid foundation for precise control of both torque and suspension forces in BIMs. The simulation and experimental results show that the algorithm not only improves the suspension performance of the BIM, but also ensures high accuracy and strong robustness. It demonstrates excellent anti-interference capabilities, particularly under varying conditions like load disturbances and abrupt speed changes.