To discuss the reactive power and voltage optimization problem in distribution power system with the doubly fed induction generators（DFIGs）

the reactive power of DFIGs

capacitor banks and on-load regulating transformers are integrated to be the control variables. The daily control time is equally distributed

so the dynamic optimization problem becomes a static optimization problem. At the time of the beginning of each period

the improved genetic algorithm is used to find the minimal active power loss. In each time period

the capacitor banks and the on-load regulating transformers are fixed

the voltages of DFIGs are used to change the reactive power. Simulation is carried out based on the modified IEEE 33-bus system

and the results show that the method proposed in this paper can reduce the distribution system power loss by providing reactive power of DFIGs.