基于激磁电流单周期内负半波持续时间特征的直流剩余电流检测新型相位差法  

A new phase difference method for DC residual current detection based on the characteristic of the duration of the exciting current negative half wave in a period

作　　者：王守相[1,2] 李皓哲 刘琪 苏伟[3] 王晨清 WANG Shouxiang;LI Haozhe;LIU Qi;SU Wei;WANG Chenqing(Key Laboratory of Smart Grid of Ministry of Education,Tianjin University,Tianjin 300072,China;Tianjin Key Laboratory of Power System Simulation and Control,Tianjin 300072,China;State Grid Jiangsu Electric Power Co.,Ltd.Research Institute,Nanjing 211103,China)

机构地区：[1]天津大学智能电网教育部重点实验室,天津300072 [2]天津市电力系统仿真控制重点实验室,天津300072 [3]国网江苏省电力有限公司电力科学研究院,江苏南京211103

出　　处：《电力系统保护与控制》2021年第11期45-53,共9页Power System Protection and Control

基　　金：国家重点研发计划项目资助(2018YFB0904700)。

摘　　要：针对直流剩余电流保护方法中传统的相位差法存在检测特征提取困难和硬件电路结构复杂的问题,提出了一种基于激磁电流一个周期内负半波持续时间特征的直流剩余电流检测新型相位差法。该方法通过检测激磁电流负半波的持续时间在剩余电流出现前后的差值来检测直流剩余电流。首先对激磁电流进行半波整流处理,将其负半波的持续时间转化为其幅值为零的时间。然后通过检测其幅值为零的持续时间在剩余电流出现前后的差值达到测量目的。基于该方法完成了直流剩余电流互感器硬件电路的设计,并通过实验验证了此方法的有效性。The traditional phase difference method finds it difficult to extract detection features and the hardware circuit structure is complex in the DC residual current protection method.Thus a new phase difference method for DC residual current detection based on the characteristic of the duration of the exciting current negative half wave in a period is proposed.In this method,the difference between the duration of negative half wave of excitation current before and after the appearance of residual current is detected to detect DC residual current.First,the excitation current is rectified by half wave,and the duration of negative half wave is converted into the duration of zero amplitude excitation current.Then,the difference between the duration before and after the appearance of residual current is detected to achieve the purpose of measurement.Based on this method,the hardware circuit of a DC residual current transformer is designed,and the effectiveness of this method is verified by experiment.

关 键 词：直流剩余电流 磁调制原理 相位差法 检测特征 

分 类 号：TM77[电气工程—电力系统及自动化]