Research On Long-term Three-phase Balancing Optimal Operation Strategy For Distribution Network

In order to solve a series of problems, such as asymmetry in three-phase voltage,reduction in distribution transformer output and the increase in network losses, which arecaused by the three-phase unbalancing in the distribution networks, a long-term three-phasebalancing optimal operation strategy for distribution network (LBOOS) based oncharacteristics of node-load curves is built in this paper. The LBOOS model includes along-term distribution reconfiguration strategy (LDRE) and long-term Three-Phase Balancingstrategy (LTPB). The LDRE focuses on improving flow distribution of network, reducing thenetwork losses and node’s voltage drop, while The LTPB focuses on improving the feederphase current’s imbalance, and further reduces the network losses and node’s voltage drop.The LDRE makes up insufficient of the conventional commutation model based on a singlepoint in time that needs to change frequently load phase.With the typical daily load model and topology mapping of the feed lines, the papersimplified the model of the network feeder line. Calculate the current value of eachthree-phase distribution transformer and node’s voltages through the three-phase flowcalculation program. Use simulated crystallizing algorithm (SCA) proposed in paper to deriveLDRE and LTPB, then implement distribution reconfiguration scheme and commutatedscheme.To verify the effectiveness of the proposed SCA based on molecular dynamic theory canimprove operating conditions of grid, IEEE-33node test feeders and IEEE-34node testfeeders are carried out. The network losses, three-phase current’s unbalance and node’svoltage drop as objective function can effectively reduce the three-phase current unbalanceand improves the voltage distribution and network losses.