Coordinated voltage optimization method in distribution network with distributed photovoltaic

Abstract

When the distributed photovoltaics enters the stage of extremely high proportion penetration, the problem of over-limit voltage in the distribution network becomes more prominent. A variety of adjustable resources in the distribution network are used in the common method to improve voltage distribution, but there is little consideration given to the information interaction between feeder layer and substation in practical engineering. Therefore, a voltage optimization method for distribution network considering the coordination between feeder layer and substation double layer is proposed in this paper. An optimal power flow model with the goal of minimizing the line loss is established in the feeder layer. The voltage at the head of the feeder layer and the injected power of the feeder layer are obtained by second-order cone relaxation, and fed back to the upper substation. A regulating voltage model is established in the substation with the goal of minimizing the voltage adjustment amount of PCC, and the adjusted voltage is returned to the feeder layer to update the power flow distribution. Then, the scheduling plan of adjustable resources are obtained. Finally, the extended IEEE 33-node power distribution system is taken as an example. The Cplex optimization solver is used to verify that the method can control the voltage and reduce the number of switching equipment. The economy of system operation on the basis of solving the distribution network voltage over-limit problem is improved.

Keywords

• double layer coordination
• information interaction
• reactive power optimization
• extremely high proportion of penetration
• over-limit voltage
• second-order cone programming