Induction Motor Control: Multivariable Analysis and Effective Decentralized Control of Stator Currents for High-Performance Applications

Abstract

The adequate control of stator currents is a fundamental requirement for several high-performance induction motor (IM) control schemes. In this context, classical linear controllers remain widely employed due to their simplicity and success in industrial applications. However, the models and methods commonly used for control design lack valuable information, which is fundamental to guarantee robustness and high performance. Following this line, the design and existence of linear fixed controllers is examined using individual channel analysis and design. The studies presented here aim to establish guidelines for the design of simple (time invariant, low order, stable, minimum phase, and decentralized) yet robust and highperformance linear controllers. Such characteristics ease the implementation task and are well suited for engineering applications, making the resulting controllers a good alternative for the stator current control required for highperformance IM schemes such as field-oriented, passivitybased, and intelligent control. Illustrative examples are presented to demonstrate the analysis and controller design of an IM, with results validated in a real-time experimental platform. It is shown that it is possible to completely decouple the stator current subsystem without the use of additional decoupling elements.

Fundamental Analysis of the Perturbation Rejection Characteristics of Single-Input-Multiple-Output Systems Subject to Multiple Perturbations

“…In this context, it is pertinent to recall that the MSF has been historically used to measure the structural robustness of multivariable systems [8][9][10][11][12][13][14][16][17][18][19][20][21]. As such, ( 0 ) → 1 is a sign of low structural robustness and it is undesired, since in that case the transmission zeros may change from minimum phase to nonminimum phase.…”

“…In some cases a bandwidth separation and nested closed-loop control allow a degree of control over several output variables. This strategy has been historically used with success in aeronautical applications and other electromechanical systems [8][9][10].…”

“…The ICAD framework allows using classical single input single output (SISO) measures of robustness and performance for multiple input multiple output (MIMO) systems. The ICAD framework allows the interpretation of complex control problems in the context of engineering systems [8,16,[18][19][20][21]. Although ICAD was originally proposed as a decentralized control design tool, in this article ICAD is adapted for the study of the SIMO perturbation rejection problem.…”

Flux-torque cross-coupling analysis of FOC schemes: Novel perturbation rejection characteristics

“…Its appropriate interpretation reveals important dynamical characteristics regarding the cross-coupling of the individual channels, including the transmission zeros, the existence of stabilizing controllers and the robustness characteristics of the closed loop control system. Some examples of the application of ICAD concepts to electrical machines can be found in [37][38][39][40].…”

Analysis of the damping characteristics of two power electronics-based devices using ‘individual channel analysis and design’

“…For further information on the ICAD framework, the reader is referred to [6] , where ICAD is presented, its use for multivariable control is discussed in detail, and an emphasis on robust stability is made; [7] , where the structural analysis for general m -input and m -output systems is discussed, the influence of right half-plane zeros on controller design and closed-loop performance is evidenced, and the existence of fixed stabilising controllers in the presence of system uncertainty is established; [8] , where the MSF characteristics for a range of 2 × 2 plants are studied; [9] , where the MSF properties are extended to the general m × m case; and to [10] , where the detailed treatment for 3 × 3 and 4 × 4 plants is examined. The framework has been successfully employed in a number of applications, ranging from submarines [11] , induction motors [12,13] and wind turbines [14,15] .…”