Method and system for evaluating stability of wind power grid-connected system during fault recovery period

The invention relates to a method and a system for evaluating the stability of a wind power grid-connected system during a fault recovery period, which belong to the field of wind power generation, and comprise the following steps of: performing low-voltage ride-through control on a direct-driven wind power grid-connected system during a fault oscillation period, converting into constant direct-current voltage control along with voltage rise, and taking a dominant oscillation mode period as a sampling interval; collecting electric quantity instantaneous value variable quantity of low voltage ride through control and constant direct current voltage control; the method comprises the following steps: constructing an energy model of each subsystem of a direct-driven wind power grid-connected system on the basis of electrical quantity instantaneous value variable quantities of low voltage ride through control and constant direct current voltage control, and obtaining interactive energy among subsystems controlled