Ac Motor Based On The Hamiltonian Method Of Energy Shaping Control

AC motor control system with high performances has made great progress and been widely applied to industrial manufacture field and domestic appliances because of the rapid development of electronic power devices, advanced control theory and computer control techniques. Permanent magnet synchronous motors are widely applied to textile, printing, national defense and other areas due to their high compactness, light weight, simple structure and convenient maintenance. But AC drivers are typical high-order, nonlinear systems with close coupling, most of the present control strategies are hard to realize due to their complexity. In the last few years, energy shaping methods are adopted to control the Hamiltonian systems and have attracted a lot of interest.In scientific research and engineering practice, energy is one of the fundamental concepts. When we study a complex and nonlinear system, the dynamic system is usually viewed as energy-transformation devices, and the complex and nonlinear system is decomposed to subsystems, which are simpler. In this paper, AC motors control system is viewed as two-port (mechanical port and electric port) energy-transformation device, speed control and position servo control system of PMSM with high performance are designed using Hamiltonian control theory and energy-shaping method.First of all, we review the development of control strategies for AC motors and energy-shaping control theory. We introduce the precise definitions of passivity, dissipation and feedback interconnection, etc, which are the theoretic basis of energy-shaping and port-controlled Hamiltonian control. We study the structure and energy balancing characteristic of port-controlled Hamiltonian system, use the interconnection and damping assignment method to determine the behavior of the system, and also present the feedback stabilization theory.According to coordinate transformation principle, models of PMSM motor are given in the stationaryαβframe and synchronously rotating reference dq frame, respectively. Then, PCH models of PMSM speed and position control system are also established in dq frame. We choose energy function of the close-loop system, render it to reach its minimum at equilibrium. PMSM speed controller and position controller, which satisfy the maximum output power theory, are designed by energy shaping and damping injection. By interconnection and damping assignment, we get the simple-structured controller of PMSM system, which involves small amount of calculation, but is easy to realize. The Hamiltonian function, interconnection and damping parameters that are chosen during the design course all have clear physical explanations in PMSM control system.Then, simulation models of control system are constructed on Matlab/Simulink software platform, and effectiveness of energy-shaping method in AC motor control system is studied. Simulation results testify the correctness and effectiveness of this approach adopted in the AC motor control systems.At last, the main work of the paper is summarized, and future research directions are proposed.