Design And Finite Element Analysis Of Cable Distributed Optical Fiber Temperature Measurement System

Under the overall situation of rapid development of power grid technology in recent decades,power cables have been widely used in many aspects such as urban power grid construction.Therefore,how to ensure the safe and reliable operation of power cables has become one of the key issues that the power grid must pay attention to..The temperature of the power cable is an important indicator that can reflect the operating conditions and transmission capacity of the cable,so real-time monitoring of the temperature of the power cable becomes particularly important.With the rapid development of optical fiber technology,distributed optical fiber temperature measurement technology has also developed rapidly.Its good electrical insulation,acid and alkali corrosion resistance,and strong resistance to electromagnetic interference are all required by the power cable temperature online monitoring system.Therefore,this paper uses distributed optical fiber temperature measurement technology to design a distributed optical fiber online temperature measurement system for power cables.According to the unique sensing characteristics of distributed optical fiber,the two principles of optical fiber Raman scattering and optical time domain reflection are explained in detail in this paper.Since the distributed optical fiber temperature measurement is only the online measurement of the temperature of the optical fiber core,the temperature model of the cable conductor is established based on the characteristics of the temperature field of the cable and the optical cable and the principle of thermoelectric coupling,combined with the principle of temperature measurement,thereby realizing the monitoring of the temperature of the cable conductor At the same time,the current carrying capacity of the cable can be obtained through the calculation of the model.In addition,this article also briefly introduces the system's structure selection and key performance parameters.In order to make the temperature measured by the cable distributed optical fiber temperature measurement system more accurate,this paper uses Monte-Carlo(MC)method to achieve accurate simulation of the Raman scattering effect,thereby establishing and improving the cable measurement system.Temperature measurement system(Distributed Optical Fiber Temperature Measurement System,DTS),and then use the improved adaptive step-length fish school algorithm to identify the parameters of the established DTS sensing model to obtain the optimal model parameters to achieve Optimized the sensing model.This paper builds an experimental platform for the research of distributed optical fiber temperature measurement system,and simulates and verifies the improved distributed optical fiber temperature measurement system.The experimental results show that the system model can realize the accurate online temperature monitoring,and then shows its measurement.The temperature sensing model is reliable and predictive.In order to ensure the validity of the established cable conductor temperature model calculation,three single-core cables of YJLW03-64/110KV-1×300mm2 type are used as examples to establish the finite element model of the temperature field of the cable and optical cable under load.The two models are simulated and analyzed separately by ANSYS finite element analysis software.The simulation results show that the model has reached the expected goal in terms of calculation accuracy,and its sensing model has been successfully improved.