The Research On Quench Protection Of High Temperature Superconducting Cable Induced By Over-Current

In the latest ten years,the research of superconducting power devices has gotten great progress.But,the using of superconducting power devices brings some new problems,especially the quench of superconducting power devices induced by large system current is a serious problem,and will harm the devices and system directly.However,the existing protection methods couldn't fill the requests of the system running.This paper takes example for the High temperature superconducting cable to research the quench protection under large system current,and puts forward a new protection strategy.Firstly,beginning with the existing quench protection methods and over-current protection of power system,the paper analyses the problems faced by the quench protection of high temperature superconducting cable,and brings forward an idea of researching the relation between over-current and temperature.Secondly,the paper analyses the temperature distribution of HTS's body under over-current and the relation between over-current,temperature and time respectively.The calculation uses six-point difference format and cell balance method.The paper designes the calculation program,and analyses the result from many points of view,establishing the theoretics base for the protection strategy.Thirdly,on the base of analysis and calculation,the paper puts forward a new protection strategy:"three- arrangement" method.And it calculates the limit temperature,limit current and cumulation,and introduces the hardware and software of the protection system.Finally,the paper introduces other two protection methods of HTS cable:distance protection and quench inspection based on tgθ.Because of the limit of the learning,this research has need to go on.Especially,the research should go deep into calculating inner temperature and stress of HTS cable,system simulation and finding new protection methods.