Islanded Operation of A Doubly-Fed Induction Generator (DFIG) Wind-Power System with Integrated Energy Storage

This paper proposes a multi-mode control strategy for a DFIG-based wind-power/storage system that enables the system to operate in (i) the grid-connected mode of operation, and (ii) the islanded mode of operation. In the grid-connected mode of operation, the wind-power/storage system can perform as an either dispatchable DG unit or a conventional (nondispatchable) wind-power unit. In the islanded mode of operation, stable islanded operation of the wind-power unit is fulfilled due to rapid response of the power-electronic converter and associated control. The advantage of the proposed control strategy is that a unified controller is employed for all modes of operation. Thus, seamless switching from one mode of operation to another is fulfilled with no need to switch between different controllers. Moreover, the proposed control scheme does not require detection signals such as islanding detection signal, battery failure detection signal, etc. The effectiveness of the wind-power/storage system and its control schemes is demonstrated through simulation studies.