(1. School of Electrical Engineering, Wuhan University, Wuhan 430072, China;2. Economic Research Institute of State Grid Hubei Electric Power Company, Wuhan 430077, China)

For the problem that the promotion of unified power flow controller is restricted by its reliability and manufacturing cost, a distributed power flow controller(DPFC)has been designed. This paper describes the topological structure and working principle of a DPFC in detail while briefly treating its characteristics and advantages. Since the location and capacity of the DPFC in the power grid directly affects its control performance, a two-stage optimization strategy for location and capacity of DPFC is proposed. First, the optimal location is determined according to the influence degree of DPFC on the power flow balance. And then the economic cost-benefit analysis is used to optimize its capacity. The feasibility and effectiveness of the proposed strategy are verified by the optimal configuration of DPFC in the IEEE 30-bus system. Simulation results show that the DPFC can effectively improve the performance of power grid after it is connected to the system.