This paper deals with the design of an extended complex Kalman filter (ECKF) for estimating
the state of an induction motor (IM) model, and for sensorless control of systems employing
this type of motor as an actuator. A complex-valued model is adopted that simultaneously
allows a simpler observability analysis of the system and a more effective state estimation.
The observability analysis of this model is first performed by assuming that a third order
ECKF has to be designed, by neglecting the mechanical equation of the IM model, which is …