数字闭环全光纤电流互感器的信号处理

Signal processing of digital closed-loop fiber optic current transducer

介绍了全光纤电流互感器的结构与工作原理,并基于光学测量原理详细讨论了方波偏置与数字闭环反馈控制。根据标准IEC 60044-8:2002在室温下对全光纤电流互感器整机进行了交流与直流下的准确度测试。测试结果表明,试品在600 A额定交流电流下比差的准确度满足0.2S级的要求;在大于5 000 A直流电流下比差的准确度在±0.1%以内。

In this paper, the structure of all fiber-optic current transducer （A-FOCT） is presented. Based on the principle of optical measurement, the square- wave modulation and digital closed-loop feedback control are discussed in detailed. According to IEC 60044-8：2002, the DC and AC accuracy of all fiber-optic current transducer is tested at the room temperature. The results show that the AC ratio error at 3 000 A rated current meets the accuracy requirement of 0.2S class ; the accuracy of DC current higher than 5 000 A is ＋0.1%. At last, the practical tentative operation in HVDC transmission is introduced. The results show that the operation is steady and the A-FOCT meets the needs of engineering applications.