Analysis of antimagnetic interference properties and structural optimization of magneto-optical glass current sensors

Abstract

To solve the issue of external magnetic fields interfering with magneto-optical glass current sensors (MOCS), this paper proposes a strip-like splicing structure. First, a mathematical model for integrating the magnetic field strength along the optical path is constructed, and the relationship between the gap size a , the interference source distance d , the angle of the interference source θ , and the relative error ε is analyzed. Then, an optical-electromagnetic COMSOL Multiphysics simulation model is constructed. The simulation results are in good agreement with the theoretical results. Finally, the strip-like splicing MOCS structure is optimized by combining two different MOCSs with a tilt angle of 45°. Thus, their output signals are summed and the adjacent interference phase signals nearly compensate mutually. This new structure facilitates real-world installation, avoiding the angle being limited to a fixed value, and meeting a 0.2 accuracy of the anti-electromagnetic interference properties.

Anti-crosstalk magnetic field method for straight-light path type optical current transducer based on the background of gas-insulated substation

“…; ðn ¼ 1;2; 3;4; 5;6Þ: (25) In this case, the zero-magnetic-interference angle of DOCT is independent of the interference distance D, and the ZMI angle is a fixed constant. This means that all positions in the ZMI angle direction outside optical current transducers are ZMI points.…”

“…The output signals of the two optical sensing structures are added during the measurement to compensate for the error generated by the adjacent phase interference signals to achieve the effect of anticrosstalk magnetic field interference. 25 However, due to the complexity of the structure, using this method creates operational stability problems. Some scholars have analyzed the structural characteristics of the point optical current transducer, differential optical current transducer, and current optical fiber transducer, their found that the crosstalk magnetic field has no effect on the measurement of the optical current transducer at a specific azimuth angle.…”

“…proposed a straight-light path type optical current transducer splicing structure, which is formed by arranging two optical sensing structures according to certain rules. The output signals of the two optical sensing structures are added during the measurement to compensate for the error generated by the adjacent phase interference signals to achieve the effect of anticrosstalk magnetic field interference 25 . However, due to the complexity of the structure, using this method creates operational stability problems.…”