Research On Electromagnetic Transient Modeling Of Superconducting Fault Current Limiter

Superconducting fault current limiter(SFCL)is one potential technology of active short-circuit current limiting measures due to its special physical characteristics.With the development of high-temperature superconductor technology,it is expected that the integration of various types of SFCL devices with different current limiting capacities and different operation voltage levels will be the major trends in the application of superconducting current limiter.In this paper,the theoretical research and model construction of the three types of current limiters are carried out,as follows:Firstly,the developing trends of the SFCL at home and abroad are investigated and analyzed.The results show that resistance-type superconducting fault current limiters(RSFCL),transformer-type superconducting fault current limiters(TSFCL)and saturated iron-core superconductive fault current limiter(SISFCL)have their own advantages.And the related superconductive materials are analyzed and discussed from the technical and economic point of view.Secondly,according to the relationships among current density,critical current and temperature for superconductive materials,the numerical models of RSFCL have been built.A case study has been carried on a 10 kV distribution network system,and the models might be validated by the testing results.The important parameters such as index value,critical temperature and synchronous failure rate of the model are analyzed.Thirdly,based on the customized model of superconducting coil in RSFCL and the analysis of current limiting impedance and heat loss,the model of TSFCL is constructed,the influence of the saturation characteristics of the core is analyzed.Compared with the RSFCL,it is expected to provide a reference for selecting the type of SFCL.Finally,the mathematical model of the SISFCL and its control system are analyzed,the simulation model is built and simulated in a 500 kV transmission system,the results show the validity of the proposed method.The influence of DC excitation current on the impedance of the current limiter is analyzed,which provides a theoretical basis for the design and evaluation of the related protection device.