Analysis And Research On Environmental Characteristics Of Key Optical Devices For FOVT

Fiber Optic Voltage Transformer(FOVT)is one of the important automatic detection devices in the field of electric power,which is crucial in acquiring,transmitting and processing information of industrial automation production,and as a prerequisite to realize the intelligence of equipment,it has become an important electrical equipment of electric locomotive and a key point of voltage measurement in electric power system.Research direction.However,the study of the relationship between environmental disturbance factors and the output characteristics of FOVT is not comprehensive,especially the lack of support for the problem of complex environmental effects under vibration and multi-physical field coupling.The study of the error characteristics of FOVT under the action of multi-physical field coupling is the key to solve the problem of its environmental adaptability,which is also a frontier problem in this field of research.Therefore,this paper takes the FOVT based on the inverse piezoelectric effect as the research object,and devotes to solving its environmental adaptability in the field of voltage sensing of electric locomotives and accelerating the improvement of its practicalization process,as follows:This paper first analyzes the principle of the key optical devices in the system,and establishes the mathematical model of the voltage to be measured and the system output.Secondly,based on the physical field characteristics of each device in the system,focuses on the analysis of the principle and performance parameters of key devices such as Faraday rotator and phase modulator that affect the system output performance.Based on the principle of Faraday rotator and phase modulator and combined with the numerical analysis method of each physical field,the output models of Faraday rotator and phase modulator under the effect of temperature and stress fields are established.Combined with the actual operating environment load of electric locomotive,the single physical characteristics and multi-physical field coupling characteristics of Faraday rotator and phase modulator and their influence law on the system output performance are analyzed.It is shown that when the temperature change rate ≤0.02℃/min,or the rotational angle error ≤0.03°,the system error caused by the environmental temperature adaptation problem of Faraday rotator does not exceed ±0.03%,when the amplitude ≤0.02g,or the rotational angle error ≤0.0127°,the system error caused by the environmental vibration adaptation problem of Faraday rotator does not exceed ±0.03%;when the temperature change rate ≤0.015℃/min,or the half-wave voltage error ≤0.01V,the system error caused by the environmental temperature adaptation of the phase modulator does not exceed ±0.03%,when the amplitude ≤0.015g,or the half-wave voltage ≤0.0113V,the system error caused by the environmental vibration adaptation of the phase modulator does not exceed ±0.03%.The results not only show the importance of Faraday rotator and phase modulator physical field stability to improve the system output performance,but also provide a reference basis for device selection and lay the foundation for system optimization and error analysis.The research in this paper is important for solving the problem of multi-physical field environment disturbance of FOVT in such as electric locomotive applications,providing certain basis and methods for suppressing multi-physical field disturbance of FOVT system and improving the output accuracy and stability of the system,as well as providing theoretical basis and technical support for accelerating the process of improving its practicalization,thus improving the operating characteristics of electric locomotives and promoting the development of electric locomotives.