【摘要】 中性点不接地系统的短时接地故障诊断十分困难,本文依据故障特性提出了一种基于最优小波包基特征提取的故障诊断新方法。该方法应用小波奇异性检测功能,确诊故障过程;以最优小波包基提取故障信息,确定特征频段;然后,建立特征频段下各线路灰关联分析的数学模型,运用灰关联分析确诊故障线路。通过对4条10kV线路的仿真分析,验证了本方法的可行性及适应性。更多还原

【Abstract】 It is very difficult to diagnose short-time grounding fault accurately for neutral point ungrounded distribution system. On the basis of fault feature, this paper presents a new fault diagnosis method, which is based on feature extraction of best wavelet packet basis. The method applies wavelet singularity detection to accurately diagnose fault process. Best wavelet packet basis is used to extract fault information and determine feature frequency band. Then, the mathematic model of grey correlation analysis under feature frequency band for various lines is established, and grey correlation analysis is used to diagnose the fault line. The feasibility and adaptability of this method are validated reliably by the simulation analysis for four 10kV lines.更多还原