Dynamic-Decoupled Current Control Based on Reduced-Order Observer for Dual Stator-Winding Induction Generator

In this paper, a dynamic current control strategy based on reduced-order observer (ROO) is proposed for dual stator-winding induction generator (DWIG), in order to suppress the disturbances and to improve the current dynamic response. Because of two stator windings, the mathematical model of DWIG is more complex and has higher order and more coupling terms, which makes poor current dynamic performance. In the proposed control strategy, by establishing the mathematical relations between the control winding (CW) current, power winding (PW) currents and rotor flux, the total disturbances of CW current are determined, observed by ROO and introduced into the current-control loop for feedforward compensation. The influence of observer parameters and parameter mismatch on the stability, rapidity and disturbance-rejection ability is also analyzed, which guides the parameter tuning of the ROO. The simulation and experiments verify the validity of the proposed current controller. The dynamic performance of is improved and the dynamic regulation time of current is shortened by more than half compared to traditional proportional-integral current controller. Moreover, the proposed current control strategy also has good robustness under the variation of machine parameters.