低压配网三相馈线损耗最小化的相别优化模型及调整方法

发布时间：2018-04-26 14:16

本文选题：低压配网 + 三相负荷不平衡　；参考：《长沙理工大学》2014年硕士论文

【摘要】：节能减排是促进经济发展的研究热点,降低配网馈线损耗对节能减排及电力系统经济运行具有深远意义。引起低压配网馈线损耗过高的主要原因之一是三相负荷不平衡。三相负荷平衡化降低配电网网损将明显改变电网运行经济性。三相负荷不平衡的产生主要是由于单相用户的用电类型复杂、用电随机性大、单相负载的大量引入以及在配网建造初期配网工作人员对负载相别的选择单凭主观经验等。目前改善三相负荷不平衡的常用方法有无功补偿设备的三相平衡化调整、三相变单相转换装置和配网用户相别调整法。配网用户相别调整法是从源头解决三相负荷不平衡问题,操作简单,实践上选用最为普遍的方法,但具体操作缺乏依据,凭主观经验进行调整。为此,考虑单相用户分散、相负荷变化随机性大、线损受线路布局及距离等因素影响,结合低压三相馈线的拓扑结构、节点支路关联矩阵和馈线损耗的计算,提出一种解决三相负荷不平衡引起线损过高的配网用户相别调整方法—三相馈线损耗模型的相别优化调整方法。在已获取用户典型日负荷曲线的基础上对同一类型用户群采用自适应惯性权重的粒子群聚类算法进行相似程度的初步聚类,将聚为同类后的用户进行相别优化调整。单相负荷接入的待定相作为优化控制变量,采用含三相电流不平衡度的线损计算公式求解各支路线损,结合拓扑结构与节点支路关联矩阵之间的联系推导低压馈线损耗随三相馈线电流变化的准确计算公式,建立了以用户接入相别为优化变量的馈线损耗之和最小的整数优化模型。通过分支定界工具箱求解整数优化模型,获得负荷最佳接入相别计算结果进行用户相别调整。该方法应用于长沙市某镇某村一台区的三相负荷平衡化改造工程,利用“用户用电信息采集系统”收集整理该台区用户的典型日负荷曲线及相关用电数据,求解模型得到该台区的用户负荷最佳接入相别计算结果进行相别调整。比较分析调整前后台区的三相电流不平衡度和馈线损耗,验证该方法能够有效降低三相负荷不平衡度,减小馈线损耗,解决三相负荷不平衡问题效果显著。
[Abstract]:Energy saving and emission reduction is the research focus of promoting economic development. Reducing the feeder loss of distribution network is of far-reaching significance to energy saving and emission reduction and economic operation of power system. One of the main reasons for the high feeder loss of low voltage distribution network is the unbalanced three-phase load. Three-phase load balance reduces the distribution network loss will obviously change the network operation economy. The unbalance of three-phase load is mainly due to the complexity of single-phase users, the large randomness of power consumption, the introduction of single-phase load, and the subjective experience of distribution network workers' choice of load phase in the initial stage of distribution network construction. At present, the commonly used methods to improve the imbalance of three-phase load are the three-phase balance adjustment of reactive power compensation equipment, the three-phase single-phase conversion device and the distribution network user phase adjustment method. Distribution network user phase adjustment method is to solve the problem of three-phase load imbalance from the source, the operation is simple, the most common method is used in practice, but the concrete operation is lack of basis, the adjustment is based on subjective experience. Therefore, considering the dispersion of single-phase users, the randomness of phase load change, and the influence of line loss on line layout and distance, combined with the topology of low-voltage three-phase feeder, the calculation of node branch correlation matrix and feeder loss, A phase optimization adjustment method for three-phase feeder loss model is proposed to solve the problem of high line loss caused by unbalanced three-phase load. On the basis of the typical daily load curve of users, the particle swarm clustering algorithm with adaptive inertial weight is applied to the same type of user group to carry out the similar initial clustering, and the users who are clustered into the same class are adjusted for phase optimization. As the optimal control variable, the undetermined phase connected by single-phase load is used to calculate the line loss of each branch by using the formula of line loss with three-phase current imbalance. Based on the relation between topology and node branch correlation matrix, an exact formula for calculating the variation of low voltage feed loss with three-phase feeder current is derived, and an integer optimization model is established, in which the sum of feed losses is minimized with user access phase as the optimization variable. The integer optimization model is solved by the branch and bound toolbox, and the load optimal access phase difference calculation result is obtained and the user phase is adjusted. The method is applied to a three-phase load balancing reconstruction project of a village and a village in Changsha City. The typical daily load curve and related data of the users in this area are collected and sorted out by "user Power Information Collection system". By solving the model, the optimal access phase difference calculation result of the user load in the station area is obtained and the phase difference adjustment is carried out. By comparing and analyzing the three-phase current imbalance and feeder loss in the front and back areas, it is proved that this method can effectively reduce the three-phase load imbalance, reduce the feeder loss, and solve the three-phase load imbalance problem effectively.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM727

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