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 is disclosed with output LC filter. The method includes determining an inverter output current vector ( iA), determining an inverter output voltage vector ( uA), and forming a full-order observer having a system matrix ( Â) and gain vector ( K). The observer produces an estimated rotor flux linkage vector ( {circumflex over (psi)}R), an estimated stator current vector ( îs), an estimated stator voltage vector ( ûs) and an estimated inverter output current vector ( îA). An estimation error ( iA- îA) of the inverter output current vector is determined, and a speed adaptation law is formed based on the estimation error of the inverter output current vector for determining an estimate for electrical angular speed ({circumflex over (omega)}m) of the induction machine. The induction machine is controlled based on the produced estimates and a measured inverter output current.