闭环光纤电流互感器误差分析与实验研究

介绍了一种电力输变电网络适用的光纤电流互感器,给出了一种基于DSP+FPGA的数字闭环信号检测方法,分析了互感器光路系统主要误差源及其相应抑制措施。依据电子式电流互感器标准IEC 60044-8,设计了互感器样机的各种准确度实验。实验结果表明:在-40～60℃范围内,样机对直流和交流电流的测量变比误差均小于±0.2%;室温条件下,直流电流测量变比误差小于0.1%,系统相位延迟约129.6′;工频电流15次以内谐波测量准确度优于0.2%,51次以内优于0.5%。研制的光纤电流互感器样机计量精度已经达到实用化要求。

Error Analysis and Experimental Research of Closed-loop Fiber Optic Current Sensor

A fiber optic current sensor suitable for electric power system is introduced.In order to improve the measurement accuracy of FOCT,a closed-loop signal detection method based on DSP+FPGA is presented.Some main error sources and corresponding suppression methods are analyzed.According to IEC 60044-8,various accuracy tests of FOCT are designed.The experimental results indicate that the ratio errors of FOCT prototype for the input AC and DC current are all less than±0.2% within -40～+60℃.At room temperature,AC current metering accuracy of prototype exceeds 0.1%,and phase delay is less than 129.6′.Measurement accuracy of FOCT for harmonic current within 51 orders is less than 0.5%.The designed FOCT prototype reaches 0.2 class in IEC60044-8 in metering accuracy.