基于分级聚类的有源配电网故障区段定位系统设计

Design of fault location system for active distribution network based on hierarchical clustering

针对有源配电网各个故障区段参数相似导致振荡不收敛的问题,设计了基于分级聚类的有源配电网故障区段定位系统。使用ARM7嵌入式CPU板,通过扩展不同外围接口实现不同通道数据采样。利用模数转换模块,将连续变量的模拟信号转换为离散数字信号形式。通过FPGA数据存储器存储离散信号数据。利用分级聚类和相似性测度方法,完成不同配电网故障区段样本集的分级聚类。引入分级聚类结果的silhouette指标,选取最优聚类结果,避免由于参数设置不合理导致振荡不收敛的问题。根据最优聚类结果,设计有源配电网故障区段定位流程。由实验结果可知,以节点编号1为例,该系统区内故障电源正序分量从故障前68.8°变化到故障后的58.6°、区外故障电源正序分量从故障前68.5°变化到故障后的57.4°,在实际正序分量变化范围内,说明设计系统故障区段定位结果精准。

Aiming at the problem of non convergence of oscillation caused by the similar characteristics of parameters in each fault section of active distribution network,a fault section location system of active distribution network is designed based on hierarchical clustering.ARM7 embedded CPU board is used to realize data sampling of different channels by expanding different peripheral interfaces.The analog-todigital conversion module is used to convert the analog signal of continuous variables into discrete digital signal.Discrete signal data is stored through FPGA data memory.Hierarchical clustering and similarity measure are used to complete the hierarchical clustering of sample sets of different distribution network fault sections.The silhouette index of hierarchical clustering results is introduced to select the optimal clustering results to avoid the problem of non convergence of oscillation due to unreasonable parameter setting.According to the optimal clustering results,the fault section location process of active distribution network is designed.According to the experimental results,taking node No.1 as an example,the positive sequence component of fault power supply in the system area changes from 68.8°before the fault to 58.6°after the fault,and the positive sequence component of fault power supply outside the area changes from 68.5°before the fault to 57.4°after the fault.Within the variation range of actual positive sequence component,it shows that the fault section positioning result of the design system is accurate.