Modified inverse decoupling control for bearingless switched reluctance motors operating in irreversible domain

Abstract

The paper proposed a modified inverse decoupling control method for bearingless switched reluctance motors (BSRMs) operating in irreversible domain. The reversibility of the model was analyzed and the irreversible domain was deduced. Then, the modified inversion was obtained via the modification of a feed-back variable. And BSRM was decoupled into two secondorder integral type displacement subsystems and one first-order integral type speed subsystem by the modified inversion. Besides, to enhance the control performance, a closed-loop compound control system was designed for subsystems. Finally, experiment results show that the proposed approach can realize decoupling control for BSRM in irreversible domain, and it has good suspension stability and regulation-speed performance.

Decoupling Control for Dual-Winding Bearingless Switched Reluctance Motor Based on Improved Inverse System Method

“…In addition, the least magnetomotive force strategy was investigated to enhance the availability of winding currents and to decrease the 2 Mathematical Problems in Engineering torque ripple and stator vibration [19]. Recently, interest in the study on decoupling control has been increasing [20][21][22][23][24], mainly including the differential geometric method [20,21] and inverse system method [22][23][24][25]. Compared with the former, the latter needs neither to use the complex nonlinear coordinate transformation nor to transfer the nonlinear control problems into geometric ones.…”

“…Therefore, the inverse system method is relatively simple to implement in practice. In detail, the inverse system method includes analytic inverse system [22,23] and intelligent ones [24,25]. Compared with analytic inverse system, intelligent ones need not rely on the precise mathematical model, but they usually require large allocations of computer resources that are often typically restricted in high-speed system.…”

“…However, it is difficult to satisfy the reversibility in practical system. According to [23], the dual-winding BSRM is not completely reversible and its working area includes two parts: reversible and irreversible domains. Traditional analytic inverse system method can only realize the decoupling control in the reversible domain, while the decoupling control in the irreversible domain cannot be realized.…”

“…Traditional analytic inverse system method can only realize the decoupling control in the reversible domain, while the decoupling control in the irreversible domain cannot be realized. To solve these issues, a modified inverse decoupling control method for BSRM operating in irreversible domain is proposed by authors in [23]. However, it is known that the analytic inverse controller usually affects the robustness and stability of system because uncertainties and model errors always exist in reality.…”

“…Especially at high-speed, the mathematical model is not equivalent to the actual system because the former does not consider the amplifiers bandwidth and computation delay, and these dynamics can degrade decoupling performance and even endanger system stability. To combat these adverse effects, proportion-integrationdifferentiation (PID) control [22][23][24][25] and internal model control [26] have been typically employed for the decoupled plants. Nevertheless, nearly all these methods experience difficulty in realizing tracking and robustness independently [27].…”