Rotor vibration unbalance compensation control of a bearingless induction motor

Abstract

Summary To handle the unbalanced vibration caused by the centroid deviation in a bearingless induction motor (BL‐IM), a dynamic unbalanced compensation strategy is proposed. Based on the traditional minimum force suppression, the best compensation value can be searched by combining with coordinate system algorithm. Firstly, the generating principle of radial suspension force and the mechanism of rotor vibration are analyzed. Then the mathematical model of dynamic imbalance compensation signal is established. Secondly, a preset compensation signal is applied to the suspension winding. The effective compensation signal that can reduce the rotor displacement is determined by measuring and calculating the corresponding variation in the rotor displacement. The effective compensation value is input into the adaptive iterative algorithm to keep approaching to the optimal compensation value. In addition, the coordinate search algorithm is used to ensure the speed and accuracy of the compensation signal calculation in the time‐varying system, which can realize the effective suppression of rotor vibration. Finally, the compensation control method is simulated in Matlab/Simulink toolbox and tested on a prototype designed by our research group. Both simulation and experimental results show that the time of motor reaching steady state is obviously shortened, and the radial deviation of the rotor is reduced during the operation of the motor. The unbalanced compensation method can effectively and quickly suppress rotor vibration.

Repetitive Control for Vibration Suppression of Bearingless Induction Motor

“…Equation (7) shows that zero steady-state tracking error can be achieved for any periodic reference signals whose frequency is less than Nyquist frequency. However, due to the different rotational speeds of the rotor, it is unable to guarantee that N is an integer for the practical use in engineering.…”

“…However, the VSS polygonal iterative seeking algorithm is complex and the computation burden is heavy. Yang et al [7] proposed a rotor vibration feedforward compensation control system based on coordinate transformation. The co-frequency vibration signals are extracted from the rotor displacement signals by coordinate transformation, and the feedforward compensator is combined to compensate the displacement signal to eliminate the vibration component in the suspension current and weaken the rotor vibration.…”

Torque System Modeling and Electromagnetic Coupling Characteristics Analysis of a Midpoint Injection Type Bearingless Permanent Synchronous Magnet Motor

“…To meet motor's long-term and high-speed operation needs, the magnetic bearing technology is widely developed [2,3], but it still has problems such as high-power consumption of magnetic suspension on and limited critical speed [3]. Te bearingless motor is a new magnetic suspension motor proposed based on the structural similarity between magnetic bearing and AC motor stator [3][4][5]. In contrast to magnetic bearing motor, the bearingless motor not only maintains the benefts of no friction and no mechanical noise but also has shorter shaft and higher critical speed.…”