Abstract: A method for designing full-order state observer for induction motor is proposed, in which the state variables are stator current and stator flux linkage. The design method for the state observer is given systematically. imulation results show that the observer has satisfactory estimation performance of stator flux. Based on the adaptive fullorder observer, a speed estimation method isobtained based on the Liapunov stability theorem. With the proposed full-order observer, the flux linkage of motor can be accurately observed and high performance achieved without shaft encoder.

Key words: direct torque con
trol, full-order state observer, pole arrangement, induction motor