Optical fiber current sensor and manufacturing method thereof

Abstract

The invention relates to an optical fiber current sensor and a manufacturing method thereof. The optical fiber current sensor comprises a first quarter wave plate, a second quarter wave plate, a sensing optical fiber and a coil frame, wherein the first quarter wave plate and the second quarter wave plate are communicated through the sensing optical fiber; the sensing optical fiber is coupled with a half-wave plate; and double wires of the sensing optical fiber double wire are wound on the coil frame in the same direction. The invention provides an optical fiber current sensor which has the advantages of high precision, small volume, light weight and no sensitivity to vibration or rotation due to no Sagnac effect and a manufacturing method thereof.

Description

technical field [0001] The invention relates to a current sensor and a manufacturing method thereof, in particular to an optical fiber current sensor and a manufacturing method thereof. Background technique [0002] With the continuous improvement of the voltage level and capacity of the power grid in the power system, the requirements for current sensors are getting higher and higher. Traditional electromagnetic current sensors have gradually exposed serious defects and cannot meet the needs of high-voltage and ultra-high-voltage power grids. In addition to the traditional electromagnetic current sensor, there is currently a Sagnac fiber optic current sensor (see figure 1 ) is in the research and development stage, and has attracted much attention as a possible replacement product of the traditional ferromagnetic current sensor, but this Sagnac-type fiber optic current sensor has not entered the stage of practical application. Because this Sagnac-type fiber optic current s...

AI Technical Summary

Problems solved by technology

[0005] The electromagnetic current sensor is mainly composed of iron core, transformer oil, copper wire and insulating medium. The volume and weight of these materials are large, and as the voltage level increases, the insulation structure becomes more and more complicated. Type current sensors are bulky and expensive

[0006] 2. There are problems of magnetic saturation and ferromagnetic resonance

[0007] Using the principle of electromagnetic induction, using the iron core structure, when the measured current increases abnormally, the sensor core will be magnetically saturated, which will seriously reduce the measurement accuracy

[0008] 3. The insulation structure is complicated and the cost is high

[0009] Due to the poor insulation of the design structure, relying on oil insulation, gas insulation and other insulation methods, as the voltage level increases, the insulation structure becomes more and more complicated, and the insulation cost rises linearly. Under the ultra-high voltage level, it is expensive and unaffordable

[0010] 4. It is not easy to connect with digital devices

[0011] The measurement result of the secondary side is also a current instead of a digital signal, so it is not easy to connect with digital equipment

[0012] 5. There is a potential explosion hazard

Because of this defect, the output change of the Sagnac fiber optic current sensor cannot be distinguished from the influence of the external environment or the change of the current itself in the high-voltage wire, which seriously affects the measurement accuracy of the current sensor and is not practical.

[0016] Therefore, these current sensors cannot meet the requirements of modern power systems, and it is urgent to find more ideal new current transformers.

Images