Control Strategy and Parameter Design of Flexible Devices in DC-Interconnected Low-Voltage Distribution Networks

The integration of high-proportion PVs brings a series of challenges for the safe operation of low-voltage distribution networks (LVDNs). It has become a trend to improve the power quality of distribution networks by using flexible interconnection technology due to large transmission capacity and flexible power regulation capability. At present, there is a lack of research on converter parameter design for DC-interconnected distribution networks. A control strategy and parameter design of flexible devices in DC-interconnected LVDNs are proposed in this paper. A control method of VSCs in one distribution area is presented to improve the voltage violations, and a control method of VSCs between two distribution areas is presented to improve overloads. The control parameters of VSCs are optimized with the objective of minimizing the network losses, including voltage and power thresholds for initiating control. The advantages of the proposed method is proved by a practical distribution network.