## Reduced-order model of cascaded doubly fed induction generator for aircraft starter/generator

Here, a reduced-order model for stand-alone cascaded doubly fed induction generator (CDFG) is presented for aircraft application, which is capable of operating in both starting and generating modes. This generator has lower maintenance cost and higher reliability, in comparison with traditional variable speed constant frequency system, based on a doubly fed induction generator (DFIG). These features make the CDFG appropriate for embedded aircraft applications. The main drawback of this generator is its inherent complexity; therefore, its analysis and control design is difficult. This complexity is due to the existence of resistances and voltage sources in the rotor loop of the full-order model. To overcome this difficulty, this study proposes a reduced-order model for the CDFG, which is similar to that of the DFIG in the synchronous reference frame. To demonstrate the efficiency of the proposed model, a field-oriented controller for CDFG is designed based on this model and compared to the full-order model. The performance and accuracy of the proposed model is validated through simulation and experimental results subject to balanced and unbalanced load change, and rotor speed variations test scenarios.