多采样率转换算法对差动保护的应用研究  

Research on the Impacts of Multi-Rate Conversion Algorithm on Differential Protection

作　　者：薛蓉[1] 

机构地区：[1]南京供电公司,江苏南京210019

出　　处：《江苏电机工程》2014年第5期62-65,共4页Jiangsu Electrical Engineering

摘　　要：智能变电站中要求合并单元的数据采集满足"一处采集,全站共享",因此合并单元数字接口必须具有采样率转换的功能,并且满足差动保护动作的要求。文中主要研究了通过抽取和插值环节的级联实现任意分数倍采样频率归一化的方法及其对差动保护差电流的影响,设计了一种零相位滤波算法以解决在采样频率转换过程中高阶FIR数字滤波器带来的群延迟较大的问题,与抽取和插值算法配合使用,可以将任意不同采样频率的ECT采样数据统一到相同的采样基准下,实现差动保护各分支采样数据之间频率的快速统一,提高保护动作的快速性。In the smart substation, data collected from any place is available for the entire substation＇ is required by data acquisition of merging unit. Therefore, the digital interface of merging units should possess the sampling rate conversion function and meet the demand of differential protection. This paper studies the mechanism of sampling rate conversion with cascade connection of decimation and interpolation. Also, the impacts of sampling rate conversion on differential current of differential protection is analyzed. To reduce group delay of high order Finite Impulse Response （FIR） in sampling rate conversion, a zero phase filtering algorithm is designed. Combining this algorithm with decimation and interpolation algorithm, the data from ECTs with different sampling rates can be converted to the same one. This achieves a unified sampling rate and improves the action speed of differential protection.

关 键 词：采样频率转换 差电流 群延迟 零相位滤波 

分 类 号：TM774[电气工程—电力系统及自动化]