Impacts Of Dfig Reactive Power/Voltage Control On Power System Oscillations Through Mode Coupling

Integration of converter-control based renew able generators (CCBGs) can affect power system small signal stability. The mechanism by which CCBG dynamics interact with synchronous generators needs careful study. This paper investigates the possibility that the reactive power control mode of a doubly-fed induction generator (DFIG) interacts with an electromechanical mode through mode coupling and affects system oscillations. Unstable inter-area oscillation caused by the interaction is demonstrated in a test system. Moreover, damping torque analysis is applied to analytically study the influence of control parameters and system operating conditions on the DFIG reactive power control mode.