A fuzzy adapted field-oriented mechanism for induction motor drive

The detuning of an indirect field-oriented induction motor drive due to variation of rotor resistance may lead to low efficiency and poor transient response. To improve this, an induction motor drive with a fuzzy adapted field-oriented mechanism is proposed. During steady state conditions, an adapted slip angular speed signal is synthesized by a fuzzy controller and used to adjust the original estimate of slip angular speed signal such that minimum stator current is obtained. When the transient due to command or load torque change occurs, the fuzzy tuning mechanism is temporarily inhibited and the final value of the adapted signal is held. A discrete two-degree-of-freedom controller (2DOF) is designed to yield good speed command tracking and load regulating responses. The effectiveness of the proposed motor drive is demonstrated experimentally.