Inverse system modeling and decoupling control of bearingless induction motor based on air gap flux orientation

Abstract

Three-phase bearingless induction motor is a multivariable, nonlinear and strong coupling object, to achieve its decoupling control with high performance, an inverse system decoupling control strategy based on air gap flux orientation is proposed. Under the conditions of air gap flux orientation of torque system, the stator currents of torque winding and suspension winding are taken as input variables, and the inverse system mathematical model of bearingless induction motor is established; adopting the inverse system method, the bearingless induction motor is decoupled into four pseudo linear subsystems, include motor speed first-order integral subsystem, air gap flux-linkage first-order integral subsystem, α and β displacement components second-order integral subsystems. The structure of decoupling control system is presented also. From the simulation results, it is clear that not only the air gap flux-linkage of torque system can be controlled accurately and directly, but also the dynamic decoupling control between motor speed, air gap flux-linkage of torque system and two radial displacement components can be achieved; Meanwhile, the control system has the characteristics of small overshoot and fast response speed.

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

“…Bearingless control technology may be used for almost all kinds of AC motors (Bu et al, 2009, 2017a; Chiba et al, 2005). Compared with other types of bearingless motor, the bearingless induction motor (BLIM) has characteristics of simple structure, larger ratio of force to current, easiness to weak magnetic, etc., and it has attracted much attention.…”

“…Motors supported by magnetic bearings have been widely developed (Bouaziz et al, 2016;Le et al, 2015), but they still have some disadvantages, such as greater magnetic suspension power consumption, limited critical speed, etc. (Bu et al, 2009(Bu et al, , 2017aSun et al, 2013). The bearingless motor is a new type of electric machine, proposed based on the similarity in structure between the conventional AC motor and magnetic bearings (Cao et al, 2009;Chiba and Santisteban, 2012;Huang et al, 2014).…”

Sliding mode variable structure control strategy of bearingless induction motor based on inverse system decoupling

“…Bearingless technology is applicable for all kinds of AC motors [12,17,20,21,27]. Because of the robust and compact structure, the bearingless induction motor has become a hot research topic [18,20], [26][27][28][29][30][31][32], but there exists a complicated electromagnetic coupling in the bearingless induction motor [30,31]. To achieve its high performance control, it is necessary to realize the dynamic decoupling between different variables.…”

“…The inverse system method is applicable for the linearization decoupling of a multivariable, nonlinear and strong coupling object. Under the rotor, air gap and stator flux orientation conditions, references have studied the inverse system decoupling methods of the bearingless induction motor. Furthermore, in order to improve the antidisturbance ability, a robust servo regulator is designed for each pseudolinear system ; however, there are no further studies on the effects of motor parameters on the control performance.…”

Stator flux orientation inverse system decoupling control strategy of bearingless induction motor considering stator current dynamics

“…The inverse system method is a feedback linearization decoupling method applied to a complex nonlinear system . There has been some research progress on the inverse system decoupling of the BLIM system . But in these studies, in order to simplify the state equation, the current dynamics of the stator winding is ignored, and therefore the dynamic decoupling performance is limited to a certain extent.…”