Multimode Control of a DFIG-Based Wind-Power Unit for Remote Applications

This paper proposes a multimode control strategy for a doubly fed induction generator-based wind-power unit, which enables operation in the islanded (autonomous) mode as well as the grid-connected mode. The configuration can be an option for electricity generation in remote communities with favorable wind conditions, but limited or unreliable connection to the grid. In the grid-connected mode, the proposed control enables the wind power unit to operate with or without battery energy storage, as desired. In case that the wind-power unit is augmented with battery energy storage, in the islanded mode, the proposed control strategy enables voltage and frequency regulation for the network, and parallel operation with constant-speed wind-power units, induction motor loads, and passive loads. The proposed control strategy employs a unified controller for all of the foregoing modes of operation and, therefore, relieves the need for switching between different controllers or reconfiguration of the hardware. The effectiveness and robustness of the proposed control strategy are demonstrated for faulted as well as normal operating conditions through simulation studies carried out on a detailed switched model of the system in the PSCAD/EMTDC software environment.