Virtual Synchronous Control Using SOGI for Standalone DFIG-Based Wind Turbines with Unbalanced and Nonlinear Loads

This paper proposes a virtual synchronous control (VSynC) strategy of a stand-alone doubly-fed induction generator (DFIG)-based wind turbine with unbalanced and nonlinear loads. By adopting the proposed VSynC strategy, the stand-alone DFIG is enabled to have an inertial response, which is similar to synchronous machines. Moreover, an integration of second-order generalized integrator (SOGI) in the virtual synchronous reference frame without any sequence decomposing process has helped in simplifying the control loop, which enables DFIG to achieve the target of sinusoidal output voltage efficiently and rapidly under islanding operation. Finally, simulation has been conducted on MATLAB to prove the feasibility of the proposed control system.