Abstract:Under external disturbances such as wind speed mutation or short-circuit fault, the shaft oscillation thereby the oscillation of output active power generally occur in grid-connected doubly-fed induction generator (DFIG)-based wind power generation system. As a result, it might lead to low-frequency oscillation in the connected power grid, and also weaken the stable operation capabilities of DFIG system and its belonged power system. In this paper, aiming at the damping characteristics related to the shaft oscillation, the motivation mechanism of the DFIG electromagnetic torque on the shaft damping was firstly deduced by using the analytical method of electromagnetic damping torque. Furthermore, this paper analyzed the influence rules of wind speed, DFIG parameters and controller parameters on the damping characteristics of DFIG. It laid the fundamental theory on design and optimization of system oscillation damping controller. Finally, the simulation results in DIgSILENT/PowerFactory verified the conclusions.
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