Interferometric Accurate Current Sensors

Abstract

Disclosed is an interference type accurate current sensor. The interference type accurate current sensor comprises a laser, fiber splitters, a detected lead, fiber coils, polarization maintaining fibers, fiber combiners and a signal processor, and is characterized in that the laser is a linear polarization laser or the output end of the laser is provided with a polarization sheet, light emitted by the laser is transmitted to the fiber splitters via the polarization maintaining fibers and is divided into four same sub-beams by the fiber splitters, the four sub-beams are respectively transmitted to one fiber coil through the polarization maintaining fibers, the four fiber coils are wound on the detected lead, the four fiber coils are staggered in terms of positions, yet the winding nodes and the numbers of turns are the same, the fiber outer surface of one of the fiber coils is provided with an electromagnetic shielding layer, the output ends of every two fiber coils are connected with one fiber combiner, the output end of each fiber combiner is respectively connected with one photodetector through fibers, and he output ends of the two photodetectors are connected with the same signal processor through a signal line.

Description

technical field [0001] The invention relates to an optical fiber current sensor, in particular to an optical fiber current sensor with accurate measurement, belonging to the field of current measurement. Background technique [0002] The rapid development of modern industry has put forward higher requirements for the transmission and detection of the power grid, and the traditional high-voltage and high-current measurement methods will face severe tests. With the development of optical fiber technology and material science, the optical fiber current sensor The system, because of its good insulation and anti-interference ability, high measurement accuracy, easy miniaturization, and no potential explosion hazard, has been widely valued by people. The main principle of the optical fiber current sensor is to use The Faraday effect of magneto-optic crystals. According to of=VBI, by measuring the Faraday rotation angle OF, the magnetic field strength generated by the current can b...

AI Technical Summary

Problems solved by technology

[0007] However, there is a problem in the fiber optic current sensors in the prior art, that is, the accuracy is not high and the stability is poor. After our analysis, the reason for these problems is mainly due to the strong external interference

For example, when measuring in the field, due to changes in the measurement environment, such as wind, it will cause the vibration of the power line and the fiber coil. These vibrations, as well as other possible vibrations, may cause changes in the polarization state of the linearly polarized light in the fiber, that is, A rotation of the plane of polarization occurs, but the resulting rotation of the plane of polarization is not due to changes in the current intensity in the transmission line, but due to disturbances, but is reflected in the current in the measurement results, resulting in the measurement There is an error in the result

[0008] The present invention is proposed aiming at the above problems, in order to solve the problems of low measurement accuracy and poor stability of optical fiber current sensors in the prior art

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