The experimental research and analysis on the quench propagation of YBCO coated conductor and coil

Quench propagation characteristics of YBCO tapes and coils were studied in this paper. Quench propagation in each test was initiated by a NiCr wire heater mounted on the sample tape and coil. Quench propagation velocity was measured through voltage taps and temperature sensors across different zones of the tapes and coil. Voltage taps and temperature sensors are arranged in longitudinal and radial direction of the coil. The thermal stability margin, the longitudinal quench propagation velocity for the tape and coil, radial quench propagation velocity for coil and the minimum propagation current were measured. In this study, we investigated the relationship between heat inputs and normal zone propagation velocities and the impact of operating currents on normal zone propagation velocities. We also compared the longitudinal quench propagation velocity and the radial quench propagation velocity. Furthermore, we performed numerical simulations by using a computer program based on a one-dimensional heat flow equation model for YBCO tape. The temperature longitudinal distributions of YBCO tape were simulated. The simulation results also prove the relation between heat input and normal zone propagation velocities and agree with the experimental results.

► Normal zone propagation velocities of YBCO tapes and coils were measured.
► The impacts of input energy and currents on quench propagate were studied.
► The thermal stability margin and the minimum propagation current were studied.
► Simulations based on a one-dimensional heat flow equation model were performed.