华电技术 ›› 2010, Vol. 32 ›› Issue (10): 18-20.

• 研究与开发 • 上一篇    下一篇

一种基于小波理论的CT饱和检测方法

练德强1,2,王建飞1,陈斌1,2,陈辉1,2   

  1. 1.杭州萧山供电局,浙江杭州311201;2.浙江大学电气工程学院,浙江杭州310016
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2010-10-25 发布日期:2010-10-25

A method for CT saturation detection based on wavelet theory

LIAN Deqiang1,2, WANG Jianfei1, CHEN Bin1,2, CHEN Hui1,2   

  1. 1.Hangzhou Xiaoshan Power Supply Bureau, Hangzhou 311201, China; 2.College of Electrical Engineering,Zhejiang University, Hangzhou 310016, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2010-10-25 Published:2010-10-25

摘要: 故障时电流互感器饱和很容易引起继电保护等装置误动。分析了电流互感器饱和机制及饱和后的二次电流特征,根据小波Mallat算法,提出了一种基于小波理论的CT饱和检测方法。该方法通过小波Mallat算法提取出二次电流的低频和高频段能量,将二者的比值构成CT饱和检测判据。PSCAD/EMTDC仿真结果表明,该方法在各种故障下均能正确检测CT是否饱和,需要的数据量较小,性能稳定。

关键词: 电流互感器, 饱和, 小波, Mallat算法

Abstract: The saturation of CT when it was faulted often causes the relay protection incorrect tripping. The saturation mechanism of CT and the secondary current characteristics of saturated CT were analyzed. According to the wavelet Mallat algorithm, a CT saturation detection method based on the wavelet theory was put forward. In this method, the wavelet Mallat algorithm was used to extract the low frequency energy and the high frequency energy of the secondary current, and their ratio is used as criterion for CT saturation detection. PSCAD/EMTDC simulation result shows that under various faults, the method can correctly detect whether the CT is saturated; the method has stable performance, and only lesser data were needed for the detection.

Key words: current transformer (CT), saturation, wavelet, Mallat algorithm