A wind generation system includes a wind turbine for generating mechanical power, a doubly-fed induction generator for converting the mechanical power to electrical power, a converter for converting the electrical power to a desired electrical power for supplying to a power grid, and a transformer through which a stator of the generator is coupled to the power grid. When a measured rotation speed feedback from the rotor of the generator is lower than an original cut-in rotation speed of the rotor, a cut-in rotation speed of the rotor is lowered by determining a DC link voltage margin of the converter, determining a DC link voltage setpoint of the converter based on the determined DC link voltage margin; and controlling the converter based on the determined DC link voltage setpoint; and/or by increasing a turn ratio of the transformer to reduce a grid voltage from the power grid.