Neural network inverse system decoupling control strategy of BLIM considering stator current dynamics

Abstract

The bearingless induction motor (BLIM) is a multi-variable, non-linear, strong coupling system. To achieve higher performance control, a novel neural network inverse system decoupling control strategy considering stator current dynamics is proposed. Taking the stator current dynamics of the torque windings into account, the state equations of the BLIM system is established first. Then, the inverse system model of the BLIM is identified by a three-layer neural network; by means of the neural network inverse system method, the BLIM system is decoupled into four independent second-order linear subsystems, include a rotor flux subsystem, a motor speed subsystem and two radial displacement component subsystems. On this basis, the neural network inverse decoupling control system is constructed, the simulation verification and analyses are performed. From the simulation results, it is clear that when the proposed decoupling control strategy is adopted, not only can the dynamic decoupling control between relevant variables be achieved, but the control system has a stronger anti-load disturbance ability, smaller overshoot and better tracking performance.

Research on the Speed Sliding Mode Observation Method of a Bearingless Induction Motor

“…According to the above analysis, when the sliding mode coefficient γ satisfies formula (19), the Lyapunov stability condition can be satisfied, and the proposed sliding mode observer is stable. In other words, through the observed rotor flux-linkage and stator current, the motor speed can be observed or identified based on the SMO method.…”

“…Under normal circumstances, two sets of windings are embedded in the BLM stator, including a set of torque windings with pole-pair number p 1 and current frequency ω 1 , and a set of suspension windings with pole-pair number p 2 and current frequency ω 2 . When the pole-pair numbers and current frequencies of the two sets of stator windings meet the "p 2 = p 1 ± 1, ω 2 = ω 1 " qualifications, the controllable magnetic suspension force and electromagnetic torque can be produced simultaneously [1,7,[16][17][18][19][20]. The controllable magnetic suspension force's generation principle is shown in Figure 1 [15,19], where the p 1 and p 2 equal to 2 and 1, respectively.…”

“…When the pole-pair numbers and current frequencies of the two sets of stator windings meet the "p 2 = p 1 ± 1, ω 2 = ω 1 " qualifications, the controllable magnetic suspension force and electromagnetic torque can be produced simultaneously [1,7,[16][17][18][19][20]. The controllable magnetic suspension force's generation principle is shown in Figure 1 [15,19], where the p 1 and p 2 equal to 2 and 1, respectively. Compared with a magnetic bearing motor, the BLM has unique advantages, such as a shorter shaft and a higher critical speed, etc., giving it bright application prospects in the high-speed-drive field [1,10,11,[21][22][23][24][25].…”

Rotor Vibration Control of a Bearingless Induction Motor Based on Unbalanced Force Feed-Forward Compensation and Current Compensation

“…A bearingless motor is a new type of motor which breaks through the balance of air-gap magnetic field of the traditional motor to produce electromagnetic torque and radial suspension force. Using the structure similarity between the magnetic bearing and the motor stator, two sets of different pole-pair windings are embedded in the bearingless motor to destroy the symmetry of air-gap magnetic field, which produces electromagnetic torque and radial suspension force and realizes the functions of rotor rotation and suspension [1]- [6].…”

Predictive current control of a bearingless induction motor model based on fuzzy dynamic objective function

“…These deficiencies limit their application in high speed and high precision fields (Sun et al, 2017). Thus, the bearingless induction motor (BL-IM) (Bu et al, 2019a) becomes the study focus. It not only has the advantages of simple structure and low cost, but also has the advantages of no friction.…”