基于改进功率树的含分布式电源配电系统孤岛划分

Island Partition of the Distribution System with Distributed Generations Based on Improved Power-tree

配电网故障后需要在短时间内做出尽可能保障关键负荷供电的策略。本文提出一种含分布式电源的配电网孤岛划分新模型及对功率树进行改进更新的方法。采用"分块—求解—修正"3步骤的求解策略:首先形成基本功率树,再利用改进方法对功率树进行合并、拓展、删除、更新操作,形成最大可能恢复供电范围的功率树分块;然后利用基于二进制的组合变异粒子群算法对功率树逐个进行最优求解;最后对形成的划分方案进行分析调节,使孤岛能稳定运行。所建立的模型计及了负荷的优先级以及功率平衡、节点电压和网络拓扑等约束,符合实际要求。利用该方法能够更快地找到全局最优划分方案。算例的计算结果验证了该方法的有效性。

It is necessary to formulate a strategy quickly to ensure the power supply for key loads as soon as possible af-ter the occurrence of fault in distribution system. In this paper,a novel island partition model of the distribution systemwith distributed generations（DGs）is proposed,together with an improved method of power-tree. A three-step strategycontaining partition,solution and adjustment is applied：firstly,fundamental power-trees are formed,and operationssuch as merging,expansion,deletion and update are realized by using the improved method,thus the power-treeblocks with the maximum regions,which are feasible to restore the power supply,are formed;then,the power-treesare processed one by one by using the binary combination/mutation particle swarm algorithm;finally,the formed parti-tion scheme is analyzed and adjusted to ensure that the island can operate stably. With the consideration of constraintssuch as the priorities of loads,power balance,nodal voltage and network topology,the proposed model can meet thepractical requirement and find the global optimal partition scheme quickly. The calculation results of a case study dem-onstrate the validity of the proposed method.