Method for enhancing optical electric current sensor stability

Abstract

A method for improving stability of an optical current sensor is used for solving stability problems in measuring high-voltage current. The technical proposal is that: a current sensing unit and a photoelectric signal processing unit composes a basic system of the sensor. The current sensing unit adopts two current sensing heads which are symmetrically arranged at both sides of the through-flow conductors; an input end of an input collimator of each current sensing head is connected with a light source. An output end of an output collimator is connected with a photoelectric signal processing unit through optical fiber and optical cable; two magneto-optic elements are manufactured with two different materials to remain a monotone functional relationship between a ratio of the verdet constant and temperature. In the invention, the method can compensate influence of the retrieval temperature on the verdet constant while an external reference source need not to be introduced, also greatly improve long-run stability while high accuracy of the sensor is guaranteed simultaneously.

Description

technical field [0001] The invention relates to a technical scheme capable of improving the measurement stability of an optical current sensor, which belongs to the technical field of measurement. Background technique [0002] Optical current sensors (OCTs) are ideal devices for high-voltage and high-current measurements. Since the 1960s, people have begun to study optical current sensors. Optical current sensors used in the power industry generally use the Faraday magneto-optical effect principle. After more than 30 years of research, great progress has been made, and there have been reports of various prototypes hanging on the net for trial operation at home and abroad. But so far, the long-term steady-state measurement accuracy of optical current sensors cannot meet the measurement requirements of power systems. The main reason is that the performance of sensors is easily affected by changes in external environmental factors (such as temperature). [0003] Chinese Pate...

AI Technical Summary

Problems solved by technology

This method can eliminate the influence of temperature in theory, but the shortcoming in practice is that the measurement accuracy depends on the long-term operation stability of the permanent magnet, strict electromagnetic shielding is required for the permanent magnet and the reference optical path, and the reference channel and the measurement channel Consistency is high

After long-term operation of the photoelectric current sensor, the optical device parameters of its two channels and the two optical paths of each channel will change inconsistently, which will have a non-negligible impact on the measurement accuracy

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