Sensorless direct vector control of an induction motor

In high-performance variable speed AC drive systems it is often important to accurately determine machine parameters and rotor speed values.An extended complex Kalman filter (ECKF) is used to estimate rotor resistance and mutual inductance without the use of a speed sensor. Such estimates are important in air gap flux orientation control. The ECKF is chosen over the more common extended Kalman filter based on the real-valued model as it is not as computationally intensive. The model of an induction machine obtained by the spiral vector theory and the ECKF are used to develop a new adaptive direct air gap flux orientation control with two sensors: one for the stator voltage and one for the stator current without Park transformation. The simulation tests show the effectiveness of the proposed adaptive direct air gap flux orientation control method.