计及分布式电源的配电网双层优化重构

Bi-level optimization of Distribution Network Reconfiguration Considering Distributed Generations

针对传统的含分布式电源(DG)配电网重构方法中存在DG安装位置、容量与重构无法兼顾的问题,提出一种计及DG的配电网双层优化重构策略;建立配电网重构的双层优化模型,其中上层优化模型以电压稳定性指标和DG并入配电网产生的网损变化量为优化目标,确定DG初始安装位置和容量,并将其作为下层优化模型的初始条件;在上层优化模型的基础上,以网损减小率最大和负荷均衡度变化量最大为目标函数对下层优化模型进行优化,确定重构后的拓扑结构;通过改进和声搜索算法对上、下层模型不断迭代实现双层优化;基于配电网重构与DG安装位置和容量存在相互制约的关系,采用6种优化场景对双层优化策略进行评估,以含DG的IEEE33节点系统为例进行仿真分析。结果表明,所提方法能使配电网重构和DG容量和位置均达到最优,有效减小配电网的网损,改善节点电压水平,提升DG的并网能力。

To solve the irreconcilable problem between the installation sites and sizes of the distributed generation (DG) and distribution grid topologies in the traditional distributed grid reconfiguration methods,a bi-level optimization strategy was proposed for distributed grid reconfiguration considering DG.In this method,a bi-level optimization model was established for the distribution grid reconfiguration containing DG,wherein the upper level of the optimized model selected the voltage stability index and the grid-loss change amount caused by DG accessed as the optimized aim to determine the initial installation sites and capacities of DG,and the lower level of the optimization model then viewed it as the initial conditions,and selected the maximized network loss reduction rate and the load balance degree variation as the optimized aim to decide the reconstructed network topology.In addition,an improved harmony searching algorithm(HSA) was applied to resolve the bi-level model through continuous iterations of the upper-level and lower-level till the expected aim would be achieved.In view of a mutual restriction between the distribution grid reconfiguration and installed locations and capacities of DG,six scenarios were described to evaluate the effectiveness of the bi-level optimization strategy.The simulation results in IEEE 33-node distributed system show that the proposed method can optimize the reconfiguration of distribution network and the capacity and position of DG,such that it can effectively reduce the grid loss,and improve the node voltage level,and enhance the ability of DG accessed to the distribution grid.