Temperature-compensation-free fiber optical current transformer and method of double-circuit interference closed loop detection

Abstract

The invention discloses a temperature-compensation-free current measurement method which uses modulation demodulation time division multiplexing technology, conducts modulation demodulation on sensing subcircuits of optical fiber sensing rings with two different temperature characteristics simultaneously, obtains measured values of the two sensing rings, and conducts digital computation according to temperature models of the two sensing rings to obtain the final measured value. The invention further discloses a device for achieving the method. The device comprises a light source, an optical fiber coupler, a two-channel phase modulator, a double refraction optical fiber delay line, the two sensing rings with different temperature characteristics, a detector and an electric signal demodulation unit, and two modulation channels of the two-channel phase modulator form two sensing subcircuits with the double refraction optical fiber delay line and one sensing ring. A temperature-compensation-free fiber optical current transformer and the method use test current demodulation values corresponding to two fiber rings with different temperature performances to calculate measurement current values without temperature influences, and accuracy, reliability and stability in a whole temperature scope are guaranteed.

Description

technical field [0001] The invention relates to the field of optical fiber sensing and the field of optoelectronic technology, in particular to a temperature-compensated optical fiber current transformer and method for dual-path interference closed-loop detection. Background technique [0002] In the context of smart grid and digital substation construction, the electronic current transformer used for power line current measurement is one of the important equipment. At present, electronic transformers are mainly divided into active electronic transformers and passive electronic transformers. Among them, passive electronic transformers use the principle of optical sensing for current measurement, and have the advantages of no electromagnetic interference, large dynamic range, The incomparable advantages of active electronic transformers, such as measurable DC, have been widely valued by the industry. [0003] There are mainly two schemes for passive optical current transform...

AI Technical Summary

Problems solved by technology

The sensing ring made of this optical fiber has good anti-stress birefringence and stable temperature characteristics. Its shortcoming is that in the whole temperature range, the change of the sensing effect ratio of the optical fiber is greater than the accuracy required by the electronic transformer measurement. range, unable to meet the measurement requirements of electronic transformers

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