融入重构级别快速识别的配电网两阶段优化运行

Two-stage Optimal Operation for Distribution Network Based on Fast Identification of Reconfiguration Level

配电网净负荷时空分布不均衡带来大规模弃光、失负荷问题,采用配电网动态重构改善潮流分布是一条有效路径,但全局动态重构在增加模型求解难度的同时,可能产生大规模潮流转移和非理想递进效益。基于此,该文提出融入重构级别快速识别的配电网两阶段优化运行策略。重构级别识别方法以优先局部自治、弃光失负荷成本最小为目标对各变电站、变压器的级别选择变量进行决策,获得配电网各时段“馈线–变压器–变电站”多级重构需求,并通过时段划分获得分时段多级重构级别评估结果。两阶段优化运行策略:第一阶段以弃光、失负荷、开关动作成本最小为目标进行分时段多级重构;第二阶段在已知全时段开关动作情况下,采用场景集对光伏和负荷的不确定性进行处理,通过可控负荷协调优化弥补第一阶段潮流分布改善能力的缺陷。最后,采用148节点系统验证了所提级别识别方法和两阶段优化运行策略的有效性。

The unbalanced spatial-temporal distribution of load demands in a distribution network may lead to photovoltaic generator(PVG) curtailment and load shedding.Dynamic reconfiguration provides a promising approach to solve those challenges by changing the power flow.However,the global dynamic reconfiguration model is difficult to solve and may result in large-scale power flow regulation with low incremental benefit.The two-stage optimal operation strategy based on fast identification of reconfiguration level was proposed.The identification method of reconfiguration level determined the “feeder-transformer-substation” level demand in each time period to prioritise local reconfiguration and minimize the PVG curtailment and load shedding.The segmented multi-level reconfiguration scheme was obtained after time division.Moreover,a two-stage optimal operation strategy was presented.In the first stage,the segmented multi-level reconfiguration aimed at minimizing the cost of switching operation,PVG curtailment,and load shedding.In the second stage,a stochastic programming model based on selected scenarios was established to address the uncertainties of PVGs and loads.The controllable load was optimized to make up for the deficiency of the first stage in improving power flow.Finally,the effectiveness of the identification method of reconfiguration level and two-stage optimal operation strategy was proved by the 148-bus system.