考虑微网出力不确定性的配电网孤岛划分

摘要

配电网发生故障后,充分利用微网对外供电能力形成孤岛,对失电区域内部分负荷进行供电恢复工作,是保证供电可靠性的基础.在考虑微网对外出力不确定性的基础上,构建了以孤岛划分方案失电负荷最小和运行约束不可靠度最小为目标的多目标优化模型,并给出一种适用于配电网辐射状约束的编码修复方法.采用拉丁超立方进化算法求解考虑微网出力不确定性的配电网孤岛划分方案,在得到Parteo非劣解集的基础上,以模糊商权方法统筹主观权重和客观权重,确定失电量和不可靠度的综合权重,决策得到最优孤岛划分方案,使得孤岛划分方法更具一般性,并且能够针对不同的偏好与现场要求给出不同方案.最后针对含多微网的PG&E69节点配电系统进行仿真,以验证所提方法的可行性.%When a failure occurs to distribution network,making full use of external power supply of micro-grid to form the island mode and restoring power supply to partial loads in the power-lost area become the basis of reliable power supply.With consideration of the uncertainty of external output of micro-grid,this paper builds a multi-objective optimization mode that aims at the minimum loss of power in the islanding scheme and the minimum value of the operation constraint unreliability and offers an encoding repair method adapting to the power distribution network to satisfy the radial constraint.Latin Hyper-cube evolutionary algorithm is used to explore the distribution network island partion program under conditions of micro-grid uncertainty.After obtaining the Pareto optimal set,subjective weights and objective weights are decided by Vague weight-quotient approach,which can determine the integrated weight of power loss and unreliability level,and work out an optimum island scheme by decision making.This method can make island schemes more generalized and be able to offer corresponding schemes according to different preferences and spot requirements.Finally,a modified PG&E 69-bus system containing micro-grid networks is used for simulation to verify the effectiveness of the proposed method.