Passivity analysis and adaptive control of brushless doubly-fed machines for adjustable speed drives

A passivity-based control(PBC)strategy with energy consideration for brushless doubly-fed machines (BDFM)is proposed.The model of BDFM described by Euler equations is also presented.The system is decomposed into two feedback interconnected passive subsystems,an electrical subsystem and a mechanical subsystem.The electrical subsystem is the unique one to be considered in designing the controllers for the torque and speed of BDFM,thus,simplifying the control algorithm.In addition,we also consider in the design the machine power and the resistance variation in the control winding during operation,thus developing an adaptive controller which makes the system robust in performance.Simulation results show that the system output tracks the reference speed quickly,with desirable static and dynamic performance,global stability as well as high robustness.