a method for the stabilization of full - order flux observers for speed - sensorless induction motors in the regenerative mode . the method comprises determining the current vector of the induction motor , determining the stator voltage vector of the induction motor , forming a full - order flux observer having a system matrix and a gain matrix , the state - variable observer being augmented with a speed adaptation loop , and producing an estimated rotor flux linkage vector and an estimated stator current vector , determining an estimation error of the stator current vector , defining a correction angle , and forming a speed adapt - tion law based on the cross product of the estimation error of the stator current vector and the estimated rotor flux linkage vector , where the correction angle is used to turn the rotor flux linkage vector or the estimation error of the stator current vector in order to keep the observer stable .