Trapped magnetic flux of bulk HTSmagnets in the external AC magnetic field at low temperatures
Trapped magnetic flux of bulk HTSmagnets in the external AC magnetic field at low temperatures
复制标题
低温下外部交流磁场中大块高温超导磁体的俘获磁通量
DOI：
10.1109/tasc.2012.2236874
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
T. Ida
中科院分区：
文献类型：
--
作者：
M. Watasaki;M. Miki;B. Felder;K.Tsuzuki;R. Sato;S. Kase;M. Izumi;T. Ida
本文以GdBa_2Cu_3O_y超导磁体为励磁极的轴流式同步发电机为研究对象，研究了电枢在交流磁场作用下的磁通俘获特性。对于三种不同的额定转速60、120和240 rpm，跟踪捕获的通量、产生的功率和温度。在60 rpm-270 W和120 rpm-600 W的操作下，捕获的通量几乎没有变化。冷却到40 K时，熔体的流量变化不大，温度也略有上升。高温超导发电机在40 K下以1 T的场极体积运行，显示出稳定的运行，这可能是适合于低频发电。然而，在240 rpm-1400 W的运行下，由于铜电枢绕组的温度升高，并且液氮冷却不能抑制电枢绕组穿过气隙的热辐射，所以本体的温度严重升高。块体的通量显示出磁化时通量的高达40%的衰减。可以通过电枢和/或转子与电枢之间的辐射屏蔽的特定设计来消除温度升高的降低。
We studied the axial-type synchronous generator with field pole bulk HTS magnets of GdBa2Cu3Oyto verify the behavior of the trapped magnetic flux due to ac field by the armature. For three different ratings 60, 120, and 240 rpm, the trapped flux, generated power and the temperatures were traced. The trapped flux showed little change with 60 rpm-270 W and 120 rpm-600 W operations. There is no remarkable change of the flux and are few rises of the temperatures of bulks cooled down to 40 K. An HTS generator operated with the field pole bulk of 1 T at 40 K shows a stable operation, which may be suitable for low-frequency power generation. However, with the operation of 240 rpm-1400 W, the temperature of bulks rises severely because the temperature of the copper armature windings increases and the liquid nitrogen cooling is not able to suppress the radiation of heat from the armature windings across the air gap. The flux of the bulks showed up to 40% decay of the flux as magnetized. The reduction of temperature rise may be eliminated with a specific design of the armature and/or a radiation shield between the rotor and the armature.