基于改进K-means聚类的配电网电压暂降频次估计法

传统考虑保护动作特性的电压暂降频次估计法需要获取详尽的保护配置信息，然而配电网保护配置多样，在不同因素如过渡电阻、运行方式、故障类型等的影响下，阶段式保护各级保护区可能产生较大变化，采用传统方法对电压暂降持续时间进行评估可能会产生较大误差。文中提出一种基于改进K-means聚类的配电网电压暂降频次估计方法，在未知线路保护配置基础上，基于电压暂降历史监测数据与保护动作信息，采用改进K-means聚类算法，对电压暂降幅值-持续时间进行聚类分析，推断线路保护配置情况，计算保护动作时间与保护动作电压。根据计算结果，在考虑不同故障类型、不同运行方式及不同过渡阻抗的情况下进行配电网电压暂降频次估计。在IEEE RBTS-6母线测试系统的母线5配电网中进行仿真，验证了文中方法的有效性和优越性。

Estimation method of voltage sag frequency in distribution network based on improved K-means clustering algorithm

The traditional voltage sag frequency estimation considering protection action characteristics needs to obtain detailed protection configuration information. However,the protection configuration of distribution network is diverse. Under the influence of different factors such as transition resistance,generator scheduling and fault type,the protection areas of each stage of stage protection may change greatly,and the traditional method may produce large error in the evaluation of voltage sag duration. In this paper,a method of voltage sag frequency estimation based on improved K-means clustering algorithm is proposed. In the case of unknown line protection configuration,based on the historical monitoring data of voltage sag and protection action information,the improved K-means clustering algorithm is used to cluster the voltage sag amplitude duration,infer the line protection configuration,and calculate the protection action time and protection action sag threshold. According to the calculation results,the distribution network voltage sag frequency is estimated considering different fault types,different operation modes and transition impedance. The simulation of the bus 5 distribution network in IEEE RBTS-6 bus test system verifies the effectiveness and superiority of the proposed method.