Fuzzy controller for inverter fed induction machines

Abstract

A fuzzy logic controller for direct self-control of an induction machine is presented. A response faster than that of the conventional direct self-controller during startup and during a step change in torque is achieved. To improve the system performance at low speeds a fuzzy resistance estimator is proposed to eliminate the error due to the change in stator resistance. At constant flux and torque commands any change in stator resistance of the induction machines causes an error in stator current. This error is utilized by the fuzzy resistance estimator to correct the stato resistance used by the controller to match the machine resistance. Both fuzzy controller and fuzzy resistance estimator are simulated for a 3 hp induction motor. The simulation results demonstrate good performance.<>