Direct decoupled active and reactive power control of Doubly Fed Induction Machine without rotor position sensors and with robustness to saturation and parameter variation

In this paper a new Direct Power Control method of the Doubly Fed Induction Machine without the use of rotor position sensors is presented. The method is based on estimating the stator flux in the rotor reference frame, and then applying the correct rotor voltages to obtain the desired rotor flux and power. Estimation of the rotor position is done by comparing the measured values with the estimated values of the rotor current. For this control method to have minimal sensitivity to parameter inaccuracies, the mutual inductance of the machine is also corrected during the process by an error signal produced by comparing the magnitudes of the measured and estimated rotor current. This will also ensures robustness against machine saturation and can be used to detect saturation in the machine.