Numerical Simulation Of The Quenching Of Superconducting Pancake YBa₂Cu₃O_7-? Coil

In practical application,HTS?High Temperature Superconductor?coil may produce a local hotspot for some thermal disturbance.In the hotspot zone,the temperature of superconductor rises over critical temperature,and the local superconductor transfers to normal.Then the current follows to resistive metal layer to produce Joule heat.Under the influence of local hotspot,the temperature may rise too high to degenerate the property of superconductor and even burn out.Therefore,studying the quenching behavior of superconductor has a profound significance on design and application.For that reason,we made a simulated study for common superconducting magnet of YBa₂Cu₃O_7-? pancake coil.The article built a COMSOL FEM model of YBa₂Cu₃O_7-? pancake coil,which used 2D-3D mixed dimensional method proposed by Wancan Chan.Basing on this FEM model,we had processed a meticulous study on quenching behavior of YBa₂Cu₃O_7-? pancake coil under the 77 K of outer temperature and studied the law of the key parameter and quenching behavior.The article stressed the quenching energy?Qhc,MPZ,MQE?and quenching propagation velocity?NZPV?.1)In most experimental study about the behavior of YBa₂Cu₃O_7-? pancake coil,generally,the researcher uses a heating wire to simulate a thermal disturbance in practice.We studied the behavior of quenching propagation in different heater parameters that includes different heater power,heater length and working pulse.Then,we concluded the critical value of Qh that makes the quenching propagate,and the regulation between Qh and heater length,heater power.2)The article studied the law of operational current with MPZ?Minimum Propagation Zone?and MQE?Minimum Quench Energy?and NZPV?Normal Zone Propagation Velocity?of YBa₂Cu₃O_7-? pancake coil.Then we analyzed the relation between heater's characteristic and MPZ,MQE,and found that the relation is feebleness.3)Considering the stabilizer's thickness of YBa₂Cu₃O_7-? coated conductor decides the Joule power of local hotpot,the article studied the quenching behavior under different thickness of stabilizer,and analyzed the relation between YBa₂Cu₃O_7-? pancake coil with MPZ,MQE,NZPV under different thickness of stabilizer.