基于双层优化规划的线路过载控制策略

Line overload control strategy based on bi-level optimization programming

对于随机故障切除后潮流转移造成的过载线路,其后备保护动作可能引发连锁故障,造成大停电事故,必须闭锁后备保护并通过线路过载控制消除过载。为减少控制策略中产生的发电机组远距离功率调节的情况,提出一种基于双层优化规划的线路过载控制策略。首先,基于支路对节点电流灵敏度矩阵构建电气距离矩阵,采用层次聚类算法进行电网分区,体现不同电气距离的发电机组对过载线路功率调节效果的差异。其次,构建双层优化规划模型,上层优化目标考虑系统功率总调节量,下层优化目标考虑各相邻区域内发电机组对过载线路区域的功率减量差值。再次,根据上层目标方程求解系统功率总调节量最小的目标值,然后通过非支配排序遗传算法(NSGA-Ⅱ)对下层优化模型进行求解,获取一组Pareto最优解集,通过满意度指标选择最优的源-荷功率调节控制方案,并实施控制方案消除线路过载。最后,基于IEEE 39标准节点系统验证所提控制策略的有效性和合理性。

For the overload line caused by power flow transferring after random fault removal,its backup protection action may cause cascading failure,resulting in blackout.Therefore,it is necessary to block backup protection and eliminate overload through overload control.In order to reduce the remote power regulation in the control strategy,an overload control strategy based on bi-level optimization programming is proposed.Firstly,the electrical distance matrix is constructed based on the current sensitivity matrix of branch to node,and the hierarchical clustering algorithm is used to partition the power grid,which reflects the difference of power regulation effect of generators with different electrical distances on overload lines.Secondly,a bi-level optimization programming model is constructed.The upper level optimization objective considers the total power regulation of the system,and the lower level optimization objective considers the power reduction difference of each adjacent region to the overload line area.Thirdly,according to the upper objective equation,the objective value of the minimum total power regulation is solved,and then NSGA-Ⅱ(Non-dominated Sorting Genetic Algorithm-Ⅱ)is used to solve the lower optimization model to obtain a set of Pareto optimal solutions.The optimal source-load power regulation control scheme is selected by satisfaction index,and the control scheme is implemented to eliminate line overload.Finally,the effectiveness and rationality of the proposed control strategy are verified based on IEEE-39 standard bus system.