YBCO涂层导体工频下过电流失超特性

为了探索YBCO涂层导体在液氮温度77 K和50 Hz 工频下的电力应用，实验研究YBCO涂层导体在不同过流冲击条件下的失超特性。YBCO涂层导体与电阻并联，再与变压器串接，电流冲击由晶闸管控制导通和关断。当晶闸管开通后，超过临界电流10倍以上的工频脉冲电流通过YBCO涂层导体持续数十至数百毫秒，记录样品上的瞬态电压电流波形。实验结果表明，在第1个半周波内，基材电阻率大的样品具有明显的限流效果，而基材电阻率小的样品没有明显的限流作用。

Quench Behavior of YBCO Coated-conductor With Over-current at Power Frequency

The quench behavior of YBCO coated conductors subjected to over-critical current with different pulse durations at 50 Hz is researched in order to explore their prospects for power application in liquid nitrogen. YBCO samples, in parallel with a resistor, are connected in series with a transformer whose current is controlled by thyristors. Current with amplitude of several tens of the critical current are fed through the samples for up to several cycles. The voltage and current profiles along the sample are recorded during its quenching. The results show that samples with high resistivity substrates have stronger current-limited capability than those of lower resistivity substrates during the first half cycle of over-current duration.