考虑负荷特性和馈线分段的配电网供电能力评估

计算配电网最大供电能力(total supply capability,TSC),除了可得出各个主变压器的负载率,还可准确描述各条馈线和各个馈线段的负荷分布。首先分析了负荷同时率对于TSC计算的影响,在此基础上建立了考虑负荷特性和馈线分段的TSC模型,该模型考虑了N-1校验和馈线段现状负荷约束。采用MATLAB线性规划函数求解TSC模型后,进一步以馈线期望负荷偏差最小为目标函数建立馈线负荷分布优化模型,采用MATLAB二次规划函数求解得出各个馈线段分配负荷值。结合馈线段现状负荷,计算馈线段可供新接入配电变压器的场景。算例结果表明本文算法能够合理均衡地分配各条馈线和各个馈线段的负荷,能够指导新用户的有序接入。数据表明现状负荷约束不仅可能改变负荷分布,还可能降低TSC值。

Evaluation of Power Supply Capability of Distribution Network Load Characteristics and Feeder Segmentation

In addition to calculating the load rate of each main transformer,total supply capacity(TSC)calculation of distribution network should also accurately describe the load distribution of each feeder and each feeder segment.Firstly,the influence of load simultaneity rate on TSC calculation is analyzed.Based on this,a TSC model considering load characteristics and feeder segmentation is established which considers constraints of N-1 check and current load of feeder segments.The linear programming function of MATLAB is used to solve the TSC model,and then the feeder load distribution optimization model is established with the minimum feeder expected load deviation as the objective function.The MATLAB quadratic programming function is used to obtain load value of each feeder segment.Based on the current load of feeder segment,calculate the scenarios where feeder segments are available for new access distribution transformer.The calculation results show that the algorithm in this paper can reasonably balance the load of each feeder and each feeder segment which can guide orderly access for new users.The data show that the current load constraints may not only change the load distribution but also reduce the TSC value.