Research On OPLC Multi-state Detection And Safe Operating State Assessment Of Optical Fiber Sensor

Optical Fiber Composite Low Voltage Cable(OPLC)technology plays an important role in the integration of network infrastructure,relying on the great advantages of natural power pipeline resources.However,there are still many challenges in the fiber-to-home power project based on OPLC technology.For example,the mechanism of sudden high temperature on the attenuation characteristics of OPLC cables has not been clearly answered,and the technical implementation of construction and maintenance of power fiber-to-home project is not well-developed.Therefore,a set of multi-state detection,operation and maintenance equipment which integrates the technical parameters of temperature,load current and optical power is developed.At the same time,the temperature characteristics of OPLC and the influence of thermal aging cables on the temperature characteristics are studied.It is of great significance to the protection of OPLC and the operation and maintenance work of power fiber-to-home project.The main research work of this paper is as follows:(1)On the basis of reviewing the research status of OPLC technology at home and abroad,this paper studies the distributed optical fiber temperature measurement technology of OPLC,current detection technology of OPLC based on current coupling mode,power measurement and detection technology of OPLC,and evaluation technology of OPLC safe operation status.(2)The hardware and software systems of OPLC state monitor developed by China Electric Power Research Institute are introduced.In order to further improve the system,an optimization scheme is proposed for the technical indicators system,such as signal-to-noise ratio and temperature accuracy,and the feasibility of the scheme is verified by experiments.The temperature accuracy of the system can be+1?,and the signal-to-noise ratio has been improved significantly by optimization verification.(3)In order to further study the temperature characteristics of OPLC and the mechanism of thermal aging effect on temperature characteristics of OPLC,COMSOL Multiphysics software is used to simulate the operation state of the composite cable,simulate the two-dimensional temperature field distribution of the composite low-voltage cable in the normal state and short-circuit state,analyze the temperature variation law of the characteristic points,and put forward the ideal model of the temperature measurement point position in the optical unit.(4)The experimental system of OPLC temperature rise was built in the pilot project,and the temperature accuracy test of oil tank was done;the variation in temperature of measuring fiber and conductor,with ambient temperature and load current is further studied.The influence of load current and ambient temperature on fiber loss is also studied.By comparing the experimental data measured in the field with the simulation data,the correctness of the model in the simulation analysis and the guiding significance of the simulation are pointed out.(5)The shortcomings of OPLC multi-level condition monitoring and safe operation condition evaluation research are summarized,and the idea of follow-up test scheme about aging OPLC composite cable is put forward.