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

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 high-performance 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 high-performance IM schemes such as field-oriented, passivity-based, 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.