基于法拉第效应的宽频光学电流传感器研制及其性能研究

Development and Performance Study of Wide-band Optical Current Sensor Based on Faraday Effect

当前智能电网和新型电力系统中存在大量高频暂态电流分量。高频暂态电流是反映电力系统扰动及故障过程的重要信息,对其波形、频率、幅值等信息参数进行实时观测是预防和确保电网安全稳定运行的前提。而传统电流测量方式存在频带窄、易受电磁干扰、绝缘配合难度大等问题,难以对暂态电流进行有效检测。故提出并设计了一种具有抗干扰能力的螺线管式宽频光学电流传感器,基于传感器性能测试平台,研究了传感器的灵敏度、线性度以及频率特性,结果表明目前传感器的灵敏度为62.57 mV/A且带宽可以达到1 MHz以上;此外搭建了直流电弧实验平台对直流电弧进行了测量。试验结果表明,该传感器可实现对直流至高频电弧分量的有效测量,其测量结果与标准电流探头的线性相关度可达0.9971,多次实验结果表明相关系数的相对变化率小于2%,具有一定工程使用价值。

At present,there are a large number of high-frequency transient current components in smart grid and new power system.High-frequency transient current is an important information reflecting the disturbance and fault process of power system,and the real-time observation of its waveform,frequency,amplitude and other information parameters is the premise to prevent and ensure the safe and stable operation of power grid.However,the traditional current measurement method has some problems,such as narrow frequency band,susceptibility to electromagnetic interference and difficulty in insulation coordination,which makes it difficult to effectively detect the transient current.Therefore,a solenoid broadband optical current sensor with anti-interference ability is proposed and designed in this paper.Based on the sensor performance test platform,the sensitivity,linearity and frequency characteristics of the sensor are studied.The results show that the sensitivity of the current sensor is 62.57 mV/A and the bandwidth can reach more than 1 MHz.In addition,a DC arc experimental platform was built to measure the DC arc.The experimental results show that the sensor can effectively measure DC to the high-frequency arc components,the linear correlation between the measurement results and the standard current probe can reach 0.9971,and the relative change rate of the correlation coefficient of many experimental results is less than 2%,which has a certain engineering value.