Transformer Type SFCL Based On Double-sided YBCO Thin Films

To meet the people's demand for electricity,power grid continues to expand,but it becomes more difficult to solve the problem of power grid failure,one of which is short-circuit fault.In solving short circuit fault,superconducting materials because of its excellent physical properties(no impedance in superconducting state and impedance in normal state)has a lot of advantages.Now the current limiting of small single-sided superconducting thin film is finite,in order to limit the larger short-circuit current,the superconducting current limiter needs large impedance.Large-area superconducting thin film can provide large impedance after quenching,but the preparation of large-area superconducting film still has some difficulties;and the multi-block superconducting thin film in series may not be able to achieve synchronization of quench.To a certain degree,double-sided superconducting film can solve the problem.Transformer-type double-sided superconducting thin film current limiting system is researched in this paper,which will apply double-sided superconducting thin film to short-circuit fault current limiting because it can fast quenching,automatically resume,synchronous quench and other properties.In this paper,the factors influencing the quench of double-sided superconducting thin films are described,and the temperature-field and electric simulation of double-sided superconducting thin films is carried out.The feasibility of the superconducting synchronization,the stability of the superconducting thin films and the mutual influence of the films are verified by experiments.Then,the law and characteristics of the transformer-type superconducting current limiter are determined by the simulation,and the regularity and characteristics of the transformer superconducting current limiter are verified by experiment.The transformer-type double-sided superconducting film can change operating current by changing the ratio.Finally,FPGA determines the working state of the transformer superconducting current limiter,by collecting the voltage signal,and output alarm signal and linkage control signal after a certain time..The results show that the double-sided superconducting thin film can promote the simultaneous quench of the double-sided superconducting thin film through the heat transfer of the base layer,and the double-sided superconducting thin film can be applied to the transformer superconducting current limiter to improve the current limiting of the current limiter.And it can change current limiter operating current by changing the ratio.It has a strong practical significance to solve the problem of short circuit current limit.