Molding. The Energy Of The Ac Motor And Nonlinear Control

Modern electrical drives based on AC motors are the most spread electromechanical systems. From the control point of view, they represent complex multivariable nonlinear problems and they constitute one of the important areas of application for nonlinear control theory. Existing solutions to these problems have been reviewed. But these methods are too complicated to be easily implemented. Recently, energy shaping methods for stabilization of physical systems have attracted a lot of interest. The main characteristic of these methods is that the system structure (Lagrangian or Hamiltonian) is preserved in closed loop. This has the advantage that the closed-loop energy function can be used as Lyapunov (or storage) function rendering more transparent the stability analysis. We focus our research on Lagrangian, Hamiltonian, backstepping and single neuron MRAC (model reference adaptive control) methods of AC motors control.1. First of all, we review the development of control strategies for AC motors. The analysis is made in four aspects, the control strategies based on steady state model, on dynamic model, independent of the mathematical model of controlled objects, modern robust and nonlinear control methods. Furthermore, the energy shaping control methods of Euler-Lagrange and port-controlled Hamiltonian systems are introduced in this paper. The future trends in the control schemes of AC motors are also proposed.2. We introduce the precise definitions of input-output stability, passivity, dissipativity, L₂-gain, energy-shaping and energy-balancing equation. Some important theories on them are presented. These reflect the fact that passivity is an energy transformation property. We describe standard mathematical expressions of the Euler-Lagrange (EL) and port-controlled Hamiltonian systems with dissipation (PCHD).3. Energy is one of the fundamental concepts in science and engineering practice, where it is common to view dynamical systems as energy-transformation devices. This perspective is particularly useful in studying...