Generic study of the power capability of a cascaded doubly fed induction machine

The paper deals with the steady state power operating margins of a cascaded doubly fed induction machine. A generic analytic method, based on a per unit representation, is suggested to derive systematically the active-reactive power domain. Therefore, the study can be applied to different ranges of doubly fed induction machines. The limit curves are defined in terms of the rated quantities of the machine. The effect of magnetic circuit saturation is further investigated. It is shown that the power capability is determined by the stator current maximum values and is subject to several limitations. The analytical approach is tested and validated by experimental measurements.