Research on Service Restoration Strategy of DC Interconnected Distribution System Considering Transfer Capabilities of VSC

Due to the maturity of voltage source converter (VSC) based multi-terminal DC (MTDC) systems, distribution networks are facing with new opportunities and challenges considering such power electronics integrations. In order to make full use of these electronic devices during grid fault problem, this paper proposes a novel restoration strategy, which is technically based on the regulation and control of VSC-MTDC, to maximize the power supply of customers in DC interconnected distribution system. Firstly, models of VSC-MTDC systems and the corresponding transfer capabilities calculation are presented. Then, a complex mixed integer non-linear programming model representing the service restoration is formulated, aiming at minimizing the total amount of load shedding, DG curtailment and power losses. Furthermore, the service restoration strategy, calculated by the optimization model, considering the active and rapid power flow regulation capabilities of VSC components is introduced into a DC interconnected distribution network represented by a modified IEEE 33-bus system. The study shows that the application of corresponding restoration strategy after the implementation of VSC-MTDC into distribution networks is able to highly improve the system reliabilities.