In this paper, two methods for controlling saturated slip power recovery drives
(SSPRD) are studied and compared. To account for saturation, a polynomial
approximation is used for the proper account of the nonlinear magnetization
reactance. Fuzzy logic (FL) is then proposed for intelligent control of the saturated
slip power recovery drive.The characteristics of the FL controlled SSPRD during
start up is presented. The FL controlled system responses to step changes in the
reference speed , load torque, and parameters variation are presented. A comparison
between the responses of a PI controlled SSPRD and the FL controlled SSPRD to
variations in reference speed, in load torque, and in rotor resistance, is obtained.
Results proved that the FL controlled SSPRD attains faster responses, accurate speed
tracking, higher load disturbance rejection, and lower sensitivity to parameters
variation', than the PI controlled SSPRD