Coupled Optimization of Topology Reconfiguration and Voltage Source Converter Control for Enlarging Load Margin of AC/DC Distribution Network

Abstract

In the AC/DC distribution network, distributed generators, energy storages, and converter-interfaced loads can be integrated flexibly. To ensure the voltage stability of the AC/DC distribution network, it is important to enlarge the load margin of ac/dc distribution network. By changing topology of the distribution network and adjusting control settings of DC links, the AC/DC distribution network may gain surpluses of the load margin without influencing the operations of distributed generators and loads connected. In this paper, a coupled optimization method is proposed to enlarge the load margin of the AC/DC distribution network, where both the topology reconfiguration and the regulation of control modes of voltage source converters (VSCs) are considered. The model of AC/DC power flow and continuous power flow (CPF) is introduced. Based on this, the optimization model for the enlarging load margin of ac/dc distribution network is presented. Then, the solving algorithm for the optimal problem is presented. Test results on a modified IEEE 33-node AC/DC hybrid system validate the effectiveness of the proposed method. Compared with optimization results using only topology reconfigurations or regulations control modes of VSCs, the load margin has been increased 14.4% and 3.8%.