In this paper

the problem of PV power station’s active output uncertain is solved by calculating expected value of the active power. By adjusting the related parameters of PV connected system to regulate the reactive power output

so to keep the PV power station can involve in reactive power optimization of distribution network. Function model with the smallest network loss as objective is established and the optimum solution of objective function is obtained by the use of modified Bacterial Colony Chemotaxis（ BCC） algorithm. The validity of the model and algorithm is verified through calculation and analysis of real examples.