Analysis And Optimization Of Temperature Stability Performance Of Fiber Optic Current Transformer

Under the support of the National High-Tech Research and Development Program,this paper uses the fiber optic current transformer for monitoring the metro power supply system as research objects.Based on the optimization and structure improvement,carrying out the key technology to research of the temperature stability of fiber optic current transformer.Firstly,establishing the optical path analysis model of the fiber optic current transformer.Based on the basic working principle of optical fiber sensing,designing a scheme of the structure and principle of the fiber optic current transformer;The Jones matrix optical path method is used to establish the analytical model of the optical path,so as to theoretically verify the structure of the optical path.During the derivation,it is found that the temperature parameters will affect the output of the model.The influence of temperature on the optical path system can be seen from the analytical model,and other factors that affect the performance of the fiber optic current transformer are also described.Secondly,optimizing the athermalizing sensor probe of the fiber optic current transformer.Aiming at the fact that the sensing fiber has a bending loss and temperature affects the stability of sensing,a kind of soft transition structure sensing fiber support is designed for the purpose of athermalization and high sensitivity,and the optimization design of the multi layer solenoid structure is carried out by theoretical calculation.COMSOL Multiphysics software is used to simulate and analyze the magnetic field distribution characteristics and temperature change rules of the sensor probe.The simulation results are compared with the calculation structure to verify the rationality of the design,and then the sensor probe is processed by the design parameters.Then,constructing the fiber optic current transformer system experimental scheme and building an experimental prototype.Based on the optical path structure model,design the experimental scheme of the all-fiber current transformer system and select the device.Combine the characteristics of the system to design the upper computer software program,and then build an all-fiber current transformer experimental prototype.The basic performance of the experimental prototype was preliminary tested.The results show that: the precision of the fiber optic current transformer system is less than or equal to 1%,The sensitivity is concentrated between 8*10-3/A and 9.5*10-3/A.At the same time,the phenomenon that the temperature of the system output waveform fluctuates strongly in the process of the experiment is described.Finally,compensating the temperature sensitivity of the fiber optic current transformer.Aiming at the temperature sensitive problem of the fiber optic current transformer,combined with the experimental phenomenon of temperature sensitivity,the output of the fiber optic current transformer under variable temperature is simulated and calculated,and the conclusion that the output of the system changes with temperature is obtained.Based on this,the BP neural network algorithm is introduced to study the intelligent compensation of the temperature sensitivity of the fiber optic current transformer,and the dynamic real-time compensation of the temperature stability of the system is realized by combining PC software.After testing,it has been found that the stability and accuracy of the system are greatly improved.