Slip power recovery system stability

A slip power recovery configuration provides an attractive alternative for variable speed drives and generating systems, due to its improved efficiency and low power converter rating. The core component is the doubly-excited machine. First, the authors present a stability analysis of the doubly-excited machine with open-loop voltage control and open-loop current control in the rotor circuit. Possibilities of open-loop control are analyzed. Second, they present a unified model of a high-performance slip power recovery system composed of a field-orientation controlled doubly-excited machine, power converters and a DC bus in the rotor circuit. The stability of this composite system represented by a model is studied. Of special interest is when the system functions as a variable-speed motor drive system or as a variable-speed constant-frequency generating system