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

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...

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

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.This work is supported by the National Key Research and Development Program of China (No. 2018YFB0904700).