NOVELTY - The system has dispatching center equipment (1) to calculate reactive power set value of wind power field according to real-time monitored voltage and active power at control point of wind power field and reference voltage. A power management module (2) distributes reactive power set value in wind power field. The controllers (3) control corresponding double-fed wind power-generating unit to perform reactive power compensation according to reactive voltage value of double-fed wind power-generating unit.    USE - Reactive voltage control system for controlling wind power field of double-fed wind power-generating unit.    ADVANTAGE - The reactive power set value is totally completed by the double-fed wind power-generating unit within the range allowed by the capacity of the double-fed wind power-generating unit, so that the reactive power output capability of the double-fed wind power-generating unit can be fully exerted, the cost of the reactive power compensation equipment of the wind power field is reduced, and the purpose of controlling the voltage of the wind power field is fulfilled. The performance of the double-fed wind power-generating unit can be improved more effectively. The parameter of the proportion integration (PI) controller module is generated by adjusting the voltage/reactive power property of the wind power field, so that the control system has quickness and stability. The overpower of the single wind power-generating unit can be avoided, the double-fed wind power-generating unit can be enabled to work in the safe power range and the output accuracy of the reactive power of the wind power field can be ensured by the distribution sub-module distributing the reactive power set value to each double-fed wind power-generating unit in the wind power field according to the equal power factor method.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for reactive voltage control method for wind power field of double-fed wind power-generating unit.    DESCRIPTION OF DRAWING(S) - The drawing shows a structural schematic diagram of the reactive voltage control system for controlling wind power field of double-fed wind power-generating unit.    Dispatching center equipment (1)    Power management module (2)    Controller (3)    Reactive power compensation equipment (4)