Output Feedback Control

Abstract

AbstractIn this chapter the state feedback controls presented in Chapter 2 and, in particular, the control given in Section 2.7 are combined with the rotor flux observers presented in Chapter 3: the goal is to obtain global output feedback controls which do not require flux measurements and guarantee rotor speed tracking for any initial condition of the motor. In Section 4.1 the global control with arbitrary rate of convergence which was presented in Section 2.7 is modified to eliminate the need of rotor flux measurements, at the expense of the property of arbitrary exponential rate of convergence. In order to recover this important property, in Section 4.2 the global state feedback control with arbitrary rate of convergence, discussed in Section 2.7, is modified so that the rotor fluxes can be replaced by the estimates provided by the rotor flux observer with arbitrary rate of convergence given in Section 3.1: the resulting observer-based global controller guarantees exponential convergence with arbitrary rate of both the tracking and the estimation errors. In Section 4.3 the control algorithm presented in Section 4.2 is made adaptive with respect to an uncertain load torque by incorporating the load torque estimator presented in Section 3.3. Finally, in Section 4.4 a global output feedback control algorithm is presented which is adaptive with respect to both the unknown load torque and the uncertain rotor resistance and achieves asymptotic rotor speed tracking. Under persistency of excitation conditions, exponentially converging estimates of the unmeasured rotor fluxes and of the uncertain parameters are obtained, while exponential tracking of rotor speed and flux modulus is achieved from any motor initial condition.KeywordsRotor SpeedTracking ErrorInduction MotorLoad TorqueRotor ResistanceThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.