Dynamic-stability enhancement and reactive power/voltage control of a large-scale wind farm using a STATCOM

This paper presents the analyzed results of using a static synchronous compensator (STATCOM) to perform both damping improvement and reactive power-voltage (Q-V) control of a large-scale wind farm (WF). The studied 80-MW WF consisting of forty 2-MW induction generators (IGs) is simulated by an equivalent 80-MW IG connected directly to a utility grid through an equivalent step-up transformer and an equivalent transmission line. Two damping controllers of the proposed STATCOM are designed by using modal control theory to contribute adequate damping to the studied WF. A systematic approach using a frequency-domain approach based on eigenvalue analysis and a time-domain scheme based on nonlinear model simulations is performed to validate the effectiveness of the proposed control scheme. It can be concluded from the simulated results that the proposed STATCOM with the designed damping controllers can not only render adequate damping characteristics to effectively stabilize the studied WF under a severe disturbance conditions but also maintain bus voltage and control the required reactive power of the studied WF.