Research On Quench And Detection Technology For SMES High Temperature Superconducting Magnet

The stable operation of high temperature superconductor magnetic energetic storage(Superconductor Magnetic Energetic Storage,SMES)device is very important to its practical application,and the quench of high temperature superconducting(High Temperature Superconducting,HTS)magnet is the primary factor that threatens the safe operation of the device.The traditional quench detection technology urgently needs to solve the difficulties: first,the change of the local quench monitoring quantity of HTS magnet is very small and difficult to monitor;second,the magnet quench voltage is prone to misjudgment of failure due to voltage disturbance.Therefore,the development of efficient and reliable HTS magnet quench and detection technology is of great significance to ensure the safe and stable operation of the SMES device.This thesis uses a combination of theoretical model and experiment to study the quench and detection technology of the HTS magnet of the SMES device,which mainly includes the following contents:First,the heat disturbances quench model of the HTS tape is established,and the quench voltage,the temperature of hot spots,normal zone propagation velocity(Normal Zone Propagation Velocity,NZPV)and minimum quench energy(Minimum Quench Energy,MQE)of the tape with one heat disturbance and two heat disturbances are studied.The results show that the greater the heat disturbance energy,the faster the quench voltage and temperature of the tape change;the greater operating current of the tape,the larger the NZPV and the smaller the MQE;the amount of heat disturbance has a weak effect on the NZPV.Secondly,an experimental platform based on the quench model of HTS tape heat disturbances is built,and the quench characteristics of the tape with one heat disturbance and two heat disturbances are analyzed.The experimental results are consistent with the calculation model,verifying the effectiveness of the heat disturbances quench model,and laying a foundation for the quench and detection technology research of the HTS magnet.Then,a new quench detection technology research based on the equivalent model of the SMES device is launched.The ratio of the high frequency component to the DC component of the HTS magnet power is selected,and two “AND” quench determination logics are designed.The change trend of the quench monitoring quantity under the operating state of the HTS magnet is analyzed.The results show that the ratio of the high frequency component to the DC component of the coil power after quench has increased by two orders of magnitude,which is an order of magnitude higher than that of the coil without quench.And as quench propagation,the greater the difference in the quench monitoring variable.The accurate positioning of the quench coil is realized.The effectiveness of the new quench detection design is demonstrated.Finally,combined with the new quench detection technology,a visual HTS magnet quench monitoring system is designed and built.The NZPV based on the heat disturbances quench experimental platform is explored.The effectiveness of the monitoring system is analyzed.The results show that the NZPV in azimuth direction of the magnet is greater than the NZPV in radial direction.The magnet monitoring system has the functions of visualization,real-time monitoring and trigger protection,which provides key technical support for the stable operation of the SMES device.