基于标准化网格曲线时频域分析的励磁涌流鉴别新方法  

Analysis of Normalized Grille Curve in Time and Frequency Domains to Identify Magnetizing Inrush

作　　者：马静[1] 王增平[1] 

机构地区：[1]华北电力大学电力系统保护与动态安全监控教育部重点实验室,保定071003

出　　处：《电工技术学报》2007年第9期159-166,共8页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(50777016);高等学校博士学科点专项科研基金(20060079009)资助项目。

摘　　要：提出了一种基于标准化网格曲线的励磁涌流识别新方法。首先对励磁涌流和短路电流的奇异特征产生机理进行了分析,并介绍了网格分形的基本概念和计算方法,然后利用该方法在提取畸变的同时,形成各自的网格曲线。在比较网格曲线变化特点的基础上,提出了两种新型变压器保护方案,即时域法和频域法。通过对网格曲线进行标准化处理,使判据定值的选取更具有普遍性,与具体变压器的参数和类型无关。动模试验计算结果表明新原理能够有效区分励磁涌流和内部故障电流,受电流互感器饱和的影响小。　A novel algorithm based on the normalized grille curve for the discrimination between inrush current and fault current is proposed. First,the singularity difference between the inrush current and internal fault is analyzed,and the grille fractal concept along with its calculation method to extract singularity characteristics is developed. Moreover,two new criteria to identify inrush current in the time and frequency domains are developed respectively in detail. The normalization of the grille curve makes the threshold has little relation with the parameter of the transformer,which has more universal meaning in the determination of the threshold. The experimental results indicate that the proposed technique is reliable during discrimination between internal faults and magnetizing inrush currents,and current transformer saturation has little influence on the technique.

关 键 词：变压器差动保护 网格分形 励磁涌流 内部故障 电流互感器饱和 

分 类 号：TM771[电气工程—电力系统及自动化]