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In the background of the global commitment to low-carbon renewable energy transformation, new energy sources such as distributed wind–solar storage and charging and single-phase loads, such as electric vehicles, are connected to the distribution network. Due to the asymmetric access of load and the randomness of load power consumption, the problem of three-phase imbalance is becoming more and more prominent, and the uncertainty is increasing. In this paper, by analyzing the three-phase load imbalance problem of the distribution network, starting from the cause of three-phase load imbalance, the three-phase imbalance calculation method of the distribution network is deduced. The access mode of a distributed power flow controller in the distribution network and the three-phase imbalance compensation method are studied. The control strategy of the distributed power flow controller for the three-phase imbalance control of the distribution network is proposed. The simulation results show that the proposed method can effectively control the three-phase asymmetry problem of the distribution network, the configuration is more flexible, and the capacity utilization rate is higher.

With large-scale access to distributed new energy, the power flow form of the distribution network tends to be complex. The distribution loop network rate increases, resulting in serious circulation of the distribution network, which places significant pressure on the loss of the distribution network. The problem of network loss change caused by distributed new energy grid connection, coupled with the inconsistency between load fluctuation and output power change of distributed new energy, will have a significant impact on the safety, reliability, and economic operation of the distribution network. Therefore, it is urgent to have good economic and technical means of power flow control. This paper proposes a minimum network loss optimization control strategy for active distribution networks based on a distributed power flow controller. First, according to the characteristics of the distribution network load and the new energy power supply along the distribution line, the multiple sub-modules of the distributed power flow controller are arranged in sections in the distribution loop network line. The regulation effect of the distributed power flow controller on the voltage and power flow of the distribution loop network is analyzed. The loop network current equation and power loss equation after the distributed power flow controller are constructed, and the power equation with the minimum active loss of the active distribution loop network is derived. Second, the control strategy for minimum network loss of the active distribution network based on the distributed power flow controller is proposed. Finally, the simulation model of the active distribution loop network is constructed by PSCAD/EMTDC. The loss of the loop network before and after the distributed power flow controller is simulated and analyzed, and the effectiveness of the proposed strategy is verified.