A Robust Sensorless Control Algorithm for Induction Generator Operating in Deep Flux Weakening Region

Compared with conventional field orientation control (FOC), the proposed algorithm achieves induction generator objectives using only one regulator based on the principle of indirect field orientation control. By means of direct control of the slip angular velocity and full utilization of the DC bus voltage, the currents projected onto the d- and q-axes are self tuned in high speed range without any conflicting regulations, resulting in stable and constant power delivering in a flux weakening level of 1/4.3. Moreover, the close-loop slip regulation automatically compensates errors from the estimation of the rotor flux angle and speed, and therefore makes the system robust. Simulation and experimental results on a 10 kW induction generator system are presented to verify the effectiveness of the proposed algorithm.