Magneto optical current transducer

Abstract

The invention relates to the field of optical current sensors, and particularly relates to a magneto optical current transducer, which comprises a laser, a ring coupler, a polarization-maintaining transmission optical fiber, a one-to-two optical fiber branching device, a magneto optical module, a ferromagnetic concentrator ring, and a differential demodulator; and the magneto optical module comprises a collimator, a polarizer, a lambda / 4 waveplate, rectangular optical glass and magnetized bodies at two ends. According to the magneto optical current transducer, based on poloidal surface magneto optical Kerr effects, the differential demodulator is matched, the magnitude of power frequency alternating current in a transmission line is indirectly detected through detecting the relative value of magnetized surface reflected light polarization deflection angles, and the detection precision and the device stability are improved.

Description

technical field [0001] The invention relates to the field of optical current sensors, in particular to a magneto-optical current transformer. Background technique [0002] With the continuous increase of power transmission capacity and the continuous improvement of grid voltage, in the face of high-voltage and ultra-high voltage grids, the traditional electromagnetic induction structure has gradually exposed many defects, such as: complex insulation measures, large volume, risk of explosion, Poor anti-electromagnetic ability and low measurement accuracy are gradually being replaced by smaller and safer photoelectric current transformers. Photoelectric current transformers are mainly divided into three types: active type, passive type and all-fiber type. [0003] The active photoelectric current transformer is a high-voltage side current signal that transmits the electrical signal to the light-emitting element through the sampling coil to become an optical signal, and then t...

AI Technical Summary

Problems solved by technology

The advantage of the all-fiber photoelectric current transformer is that the structure of the sensing head is the simplest, and it is easier to manufacture than the passive type. The disadvantages, such as the optical fiber itself and the optical fiber winding effect, linear birefringence and other optical effects, affect the accuracy of the measurement. and stability

[0006] All of the above methods have been used, and some have been connected to the grid for operation, but so far they have not been successfully promoted and applied in my country's power grid

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