A double-fed induction machine with a multistage-multilevel frequency converter for pumped storage power plant applications

The paper presents the modeling and simulation study of a variable speed drive for the pump-storage station composed of a reversible turbine and a doubly fed induction machine (DFIM) exited with a multistage-multilevel frequency converter. The DFIM is started up as a synchronous machine by means of a CSI on the stator side and a VSI on the rotor side. An emphasis is placed on the control system structure aimed at the active and reactive power regulation via a mechanical governor and a slip controller. The paper concludes by analyzing start-up responses and performance characteristics of the system in sub- and over-synchronous modes of operation.