Research On Quench Detection Of HTS Cable Based On Distributed Optical Fiber Temperature Measurement Technology

The quench detection system of HTS cable has important engineering significance for the stable operation of the HTS cable.The traditional voltage measurement method is easy to be affected by the electromagnetic interference caused by high voltage and high current,and it can not realize the continuous distributed measurement along the cable length.The distributed optical fiber temperature measurement technology(DTS)can realize the continuous measurement of the space temperature field by using the temperature detection method.Therefore,the DTS can be applied to the quench detection of HTS cable.In this thesis,the performance of fiber temperature measurement in low temperature and the practical application are studied according to the requirements of the HTS cable.The main research contents are as follows:(1)The sensing performance of different coating fiber at low temperature is studied.The reflected light signal at low temperature is improved by signal optimization method.Then,the temperature calibration experiment of the sensing fiber is carried out from77K-300 K,and the function of low temperature measurement of optical fiber is realized by curve fitting.(2)The actual measurement performance of DTS at low temperature is studied,including spatial resolution,time resolution,temperature resolution,positioning accuracy and fiber bending limit,etc.The feasibility of the DTS for actual temperature measurement at low temperature is verified.(3)In the simulation of practical application,a 1m long HTS cable is wound,which combines the sensing fiber with the HTS cable.The feasibility of DTS in the quench detection of HTS cable is verified by DC impact test of HTS cable.At the same time,the influence of different impact voltage and different impact time on the quench process of HTS cable is compared.This thesis has carried on the exploratory research on the application of optical fiber temperature measurement technology at low temperature.The experimental conclusion and results provide technical support for the quench detection of HTS cable,which has important practical significance.