Stability analysis and application of a synchronverter-based control approach to DFIG-based wind energy conversion systems

This work proposes an enhanced control approach relying on the synchronverter concept for wind energy conversion systems (WECSs) based on the doubly-fed induction generator (DFIG). It consists of incorporating a virtual filter resistor into the control loop of the synchronverter, which is associated with the grid-side converter (GSC) aiming at emulating the behavior of a synchronous generator when providing ancillary services such as frequency support. A comprehensive state-space representation is derived to demonstrate that the virtual filter resistor is essential to ensure stability. After the proper adjustment of the model, it is possible to verify the effectiveness of the synchronverter-based control applied in the IEEE 14-bus modified system employing parameters obtained from a real power plant. The results show that the application of the introduced method results in less severe frequency dips and faster transient response during frequency support even when compared with the case in which only synchronous machines are connected to the grid.