High-precision high-reliability and all-fiber current transformer

Abstract

The invention belongs to the technical field of all-fiber current transformers, and particularly relates to a high-precision high-reliability and all-fiber current transformer. A redundancy design method adopting active optical devices is applied so that output optical power of light source units is enabled to be more stable and stability of light source average wavelength is enhanced. A depolarization head is additionally arranged in an optical path system so that stability and measurement precision of the optical path system can be enhanced. Two beams of light are converted into electric signals to be transmitted to a signal processing unit by utilizing correlation of output light of the two output ends of a second single-mode coupler through a digital signal processing unit, and suppression of light source intensity noise is realized by utilizing a digital circuit subtraction method so that signal-to-noise ratio is enhanced and measurement precision of the system is enhanced. A low birefringence optical fiber Verdet constant and a transformation ratio error generated by change of wave plate phase delay along with temperature are enabled to be mutually compensated via an all-fiber current transformer transformation ratio temperature error automatic compensation technology so that full-temperature measurement precision of the system is enhanced.

Description

technical field [0001] The invention belongs to the technical field of all-fiber-optic current transformers, and in particular relates to a high-precision and high-reliability all-fiber-optic current transformer. Background technique [0002] The construction of smart grid is one of the seven strategic emerging industries to be cultivated in my country's "Twelfth Five-Year Plan". Digital substation is the main component of smart grid. In the State Grid's "Building a Strong Smart Grid" plan, a "five vertical and six horizontal" UHV transmission backbone grid will be formed in 2020, and a strong smart grid will be built in an all-round way, so that the resource allocation capability, security level, and operation of the grid will be improved. Efficiency and user interaction are significantly improved. [0003] In the smart grid, "advanced sensing and measurement technology" is one of the key technologies, and the current transformer has become the key equipment for the const...

AI Technical Summary

Problems solved by technology

[0005] At present, all-fiber current transformers have exposed many problems in the actual application process: the light source wavelength changes with temperature, the output power is unstable, the light source intensity noise, the measurement accuracy of the system changes with the external environment temperature, and the small current measurement accuracy is poor. The impact of low operating reliability on secondary applications such as protection and measurement may lead to protection blocking and operating value errors, which have become key factors affecting the application and promotion of all-fiber current transformers

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