Combined magnetising flux oriented control of the cascaded doubly-fed induction machine

A cascaded doubly-fed induction machine (CDFM) is a connection of two wound rotor induction machines. In comparison to a single doubly-fed (wound rotor) induction machine (SDFM) brushes are obsolete. Because of recent developments in brushless doubly-fed machine design, there is a renewed interest in associated control. The paper presents theoretical and experimental studies of a combined magnetising flux oriented control method for a CDFM. After the existing control method has been described it is then modified to be applicable to any CDFM machine combination. In a second step the control method is simplified and the performance is explored. Investigations of a power control loop for the simplified control show that this control method does not lead to natural decoupled active and reactive power control as known from the SDFM.