All-fiber current transformer and half-wave voltage correction method thereof

A current transformer and half-wave voltage technology, which is applied in the field of all-optical current transformer and its half-wave voltage correction, can solve the problems of low accuracy and low efficiency of half-wave voltage, and achieve the effect of improving measurement efficiency and accuracy

CN112816758APending Publication Date: 2021-05-18XUJI GRP +1
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2021-05-18

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Abstract

The invention relates to an all-fiber current transformer and a half-wave voltage correction method thereof, and belongs to the technical field of power system automation. The correction method comprises the following steps: before operation, acquiring emergent light in real time, and calculating a light intensity value of the emergent light and an additional light intensity difference, wherein the extra light intensity difference is the difference between the light intensity value of the first transition period after 2[pi] overflow and the light intensity value of the last transition period before 2[pi] overflow; and taking the extra light intensity difference as zero as a target, correcting the half-wave voltage, completing the initialization process, obtaining a corrected half-wave voltage value, and taking the corrected half-wave voltage value as the initial half-wave voltage during operation to measure the current. Before the current is measured by the all-fiber current transformer, the half-wave voltage is corrected by taking zero extra light intensity difference as a target, and the initialization process is completed. If the deviation of the half-wave voltage is large, correction of the half-wave voltage is completed before measurement, so that the measurement efficiency and accuracy of the current are improved.
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Description

technical field

[0001] The invention relates to an all-fiber current transformer and a half-wave voltage correction method thereof, belonging to the technical field of power system automation. Background technique

[0002] The current transformer is one of the most critical power transmission and transformation equipment in the power system. It is widely used in relay protection, current measurement and power system analysis. With the rapid development of the power system, the traditional electromagnetic induction current transformer has continuously exposed a series of shortcomings: poor insulation performance, low resistance to electromagnetic interference, small dynamic range, narrow frequency band, unable to measure DC, etc., it is difficult to meet the new requirements. The development needs of a generation of power system on-line detection, high-precision fault diagnosis, and power grid digitization.

[0003] Therefore, it is urgent to develop new electrical measureme...

Examples

Embodiment Construction

[0033] All fiber optic current transformer embodiment:

[0034] The all-fiber-optic current transformer proposed in this embodiment includes a light source, an optical-fiber sensing ring (sensing ring for short), a phase modulator, a photodetector, and a controller. The controller includes a memory and a processor, and the processor is used to execute instructions stored in the memory to realize the half-wave voltage correction method of the all-fiber current transformer.

[0035] The all-fiber-optic current transformer utilizes Faraday's magneto-optic effect principle and interferometry principle to close-loop control the internal optical signal, and demodulates the implied current information from it. The specific structure of the all-fiber current transformer is as follows: figure 1 As shown, it includes an electronic circuit, an optical circuit, and a sensing ring; the optical circuit includes an SDL light source, a phase modulator, and a fiber optic detector; the electro...