Speed sensorless control of an induction machine using a PWM inverter with output LC filter

A method of controlling of an induction machine using an inverter with output LC filter. The method comprising the steps of determining the inverter output current vector ( i A ), determining the inverter output voltage vector ( u A ), forming a full-order observer having a system matrix ( Â ) and gain vector ( K ), the observer producing the estimated rotor flux linkage vector ( ¨ R ), the estimated stator current vector ( î s ), the estimated stator voltage vector ( û s and the estimated inverter output current vector ( î A ), determining the estimation error ( i A - î A ) of the inverter output current vector, forming a speed adaptation law based on estimation error of the inverter output current vector for determining the estimate for electrical angular speed (É m ) of the induction machine, and controlling the induction machine based on the produced estimates and the measured inverter output current.