A Two-stage Power Flow Optimization Method for Active Distribution Network Considering Distribution Network Reconfiguration

In order to solve the problems of increasing network loss, increasing voltage deviation and serious wind and solar power curtailment caused by the high proportion of distribution generation (DG) access to the distribution network, a two-stage power flow optimization method for active distribution network considering distribution network reconfiguration is proposed. The first stage focuses on the economy of the distribution network operation, taking the minimum network loss, the minimum amount of wind and solar power curtailment, the minimum equipment operation cost and the minimum power purchased from the superior grid as the objective function. On the basis of coordinated optimization of discrete control devices such as on-load tap changer (OLTC), capacitor bank (CB) and contact switch, the active power output of DGs and energy storage systems (ESS) are considered to obtain the operation scheme of the first stage. The second stage focuses on the safety of distribution network operation. According to the operation scheme of the first stage, with the minimum network loss and minimum voltage deviation as the objective function, the continuous reactive power output of DG, static var compensator (SVC) and ESS is coordinated and optimized to obtain the operation scheme of the second stage. Finally, an improved IEEE 33-node distribution system is used to simulate and verify the effectiveness of the method.