Converter negative sequence reactive power control method and device during power grid fault ride-through

The invention relates to a negative sequence reactive power control method and device for a converter during power grid fault ride-through, and belongs to the technical field of power electronics. The three-phase voltage of the power grid is calculated, the calculation result is converted into a negative-sequence reactive current instruction under a positive-sequence dp coordinate and a negative-sequence active current instruction under the positive-sequence dp coordinate, and the negative-sequence reactive current instruction and the negative-sequence active current instruction are subtracted from a power grid reactive current component and a power grid active current component respectively; and finally, carrying out closed-loop regulation control on the two difference values through corresponding regulators respectively, superposing results to outputs of corresponding current inner loops respectively, and carrying out positive-sequence dq coordinate conversion on calculation results. A negative-sequence rea