离相封闭母线大电流的光测系统及传感研究

本文阐述了离相封闭母线壳内空间的磁场仅与母线电流有关的特征。论述了在壳内设置基于光学方法的电流传感器、实现非接触光测大电流的系统及其优越性。本文按半经典理论推出磁场作用下的传感媒质的复介电系数、复折射率以及对左、右旋光的吸收差异。论证了磁光传感的普遍形态是将线偏振光转变为一个发生磁旋转、振幅衰减的线偏光与一圆偏光的叠加——椭圆偏振。分析了对交、直流不同情况实现大电流的光测的不同处理方法。最后,推出交、直流的光测大电流公式。

Research of the Optical Measuring System and Sensing for Large Current in the Isolated Phase Bus

This paper describes the fact that the magnetic field in the isolated phase bus is only related to the bus current. The non-contact optical measuring system is realized by the current sensor in the isolated bus . The superiority of the system is discussed. The complex dielectric constant and refraction index of the medium, as well as the absorption coefficients of the left and the right circularly polarized light in the medium are deduced according to the semi-classical theory. The general expression of the Faraday Effect which can transform the incident linearly polarized light into the superposition of the attenuated, linearly polarized light and the circularly polarized light is obtained. The different treatments of the optically measured large current in accordance with AC and DC are analysed and the formulas of which are given.