Inhomogeneous-field-induced Media Model And Optical Current Sensing Characteristics

The optical current transformer is based on Faraday's magneto-optical effect.It has the advantages of accurate measurement,safe insulation,easy integration,convenient physical network connection,etc.It is an excellent electronic current transformer,representing the important development direction of current transformer.Under the progress of science and technology and the unremitting efforts of researchers,the research work of optical current transformers has achieved important practical results.However,there is still a gap in the popularity of applications.One of the problems is that the uneven magnetic field has adverse effects on measurement accuracy.This paper focuses on the research of the non-uniform magnetic field of optical current transformers.In this paper,the academic research route is that general magnetic field comes first and then magnetic field,the portion comes first and then the whole.The Jones matrix of inhomogeneous-field-induced media is studied.The Sensing characteristics of optical current transformer in inhomogeneous magnetic field are analyzed.Firstly,the basic properties of the Jones matrix with inhomogeneous-field-induced media are analyzed by the micro-level cascade method.It is pointed out that the inhomogeneous-field-induced media are different from the uniform media for that the non-diagonal elements of the Jones matrix are complete complex number.It is the consequence of the eigenvalue coordinate system changing along the optical path.Secondly,the ternary model of the Jones matrix of inhomogeneous-field-induced media is established through unitary transformation.The ternary model which has no redundancy is accurately described by the three independent physical parameters: the medium's phase delay,induction angle and inhomogeneous angle.The concept of magnetic field inhomogeneity is defined.The relationship between magnetic field inhomogeneity and medium's inhomogeneous angle is studied.It is pointed out that the medium's inhomogeneous angle can characterize the unevenness of the physical field on the whole medium.Thirdly,the optical path integral formula of three physical parameters is deduced.The optical path integral formula reveals the relationship between the overall three parameters of the medium Jones matrix and the section induction tensor.The simulation comparison between the integral formula and the micro-element cascading model shows partial rationality and accuracy of the integral formula.Compared with the distributed parameter model,the integral formula doesn't change the unitary matrix property of the Jones matrix.And it also has broader application.Finally,the non-uniform magnetic field sensing model of the magneto-optical glass optical current transformer is established based on the ternary model.It is pointed out that the optical path output of optical current transformer is different when the magnetic field distribution changing from uniform to uneven.The latter is affected by the medium's inhomogeneous angle.The optical sensing output simulation study shows that the magnetic field sensing component based on the inductive inhomogeneous model is closer to the micro-scale cascade model's.It means the higher current sensing accuracy.