Control method for double-feed wind power generation unit to support reactive power regulation of wind farm

The invention relates to a control method for a double-feed wind power generation unit to support reactive power regulation of a wind farm, which comprises the steps that: that if a double-feed wind power generator is connected to a power grid is judged; if the generator is not connected and Oref is more than Ogmax, Qgref is equal to Qgmax; if Qref is not more than Qgmax, Qgref is equal to Qref; if the power generator is connected to the power grid, when Qref is less than Qsmax, Qsref is equal to Qref and Qgref is equal to 0; when Qref is more than Qsmax, Qsref is equal to Qsmax, and Qgref is equal to Qref minus Qsref, and a reference value of variable current on the side of the grid is no more than a reactive power limit when the current runs. The invention can enable the double-feed wind power generation unit to play the role of supporting the reactive power regulation of the wind farm when the power generator is not connected to the power grid, so that the reactive power instructions of the unit are distributed between the power generator and a grid side converter, the safety operation of a system is ensured, the utilization rate of the equipment of the wind power unit is fully improved, and the investment cost of the reactive equipment of the wind farm is reduced.