A high-precision and high-reliability all-fiber optic current transformer

Abstract

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. By adopting the redundant design method of the active optical device, the output optical power of the light source unit is more stable, and the stability of the average wavelength of the light source is improved. By adding a depolarization head in the optical path system, the stability and measurement accuracy of the optical path system are improved. Through the digital signal processing unit, the correlation of the output light of the two output ports of the second single-mode coupler is used to convert the two beams of light into electrical signals and send them to the signal processing unit, and the digital circuit subtraction method is used to suppress the noise of the light source intensity and improve The signal-to-noise ratio is improved, and the measurement accuracy of the system is improved. Through the automatic compensation technology of the ratio temperature error of the all-fiber current transformer, the Verdet constant of the low birefringence fiber and the ratio error caused by the wave plate phase delay with the temperature change are mutually compensated, thereby improving the full temperature measurement accuracy of the system.

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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