TY - JOUR
T1 - Ramping turn-to-turn loss and magnetization loss of a No-Insulation (RE)Ba2Cu3Ox high temperature superconductor pancake coil
AU - Wang, Yawei
AU - Song, H
AU - Yuan, Weijia
AU - Jin, Z
AU - Hong, Z
PY - 2017
Y1 - 2017
N2 - This paper is to study ramping turn-to-turn loss and magnetization loss of a no-insulation (NI) high temperature superconductor (HTS) pancake coil wound with (RE)Ba2Cu3Ox (REBCO) conductors. For insulated (INS) HTS coils, a magnetization loss occurs on superconducting layers during a ramping operation. For the NI HTS coil, additional loss is generated by the ‘bypassing’ current on the turn-to-turn metallic contacts, which is called “turn-to-turn loss” in this study. Therefore, the NI coil’s ramping loss is much different from that of the INS coil, but few studies have been reported on this aspect. To analyze the ramping losses of NI coils, a numerical method is developed by coupling an equivalent circuit network model and a H-formulation finite element method (FEM) model. The former model is to calculate NI coil’s current distribution and turn-to-turn loss, the latter model is to calculate the magnetization loss. A test NI pancake coil is wound with REBCO tapes and the reliability of this model is validated by experiments. Then the characteristics of the NI coil’s ramping losses are studied using this coupling model. Results show that the turn-to-turn loss is much higher than the magnetization loss. The NI coil’s total ramping loss is much higher than that of its insulated counterpart, which has to be considered carefully in the design and operation of NI applications. This paper also discusses the possibility to reduce NI coil’s ramping loss by decreasing the ramping rate of power supply or increasing the coil’s turn-to-turn resistivity.
AB - This paper is to study ramping turn-to-turn loss and magnetization loss of a no-insulation (NI) high temperature superconductor (HTS) pancake coil wound with (RE)Ba2Cu3Ox (REBCO) conductors. For insulated (INS) HTS coils, a magnetization loss occurs on superconducting layers during a ramping operation. For the NI HTS coil, additional loss is generated by the ‘bypassing’ current on the turn-to-turn metallic contacts, which is called “turn-to-turn loss” in this study. Therefore, the NI coil’s ramping loss is much different from that of the INS coil, but few studies have been reported on this aspect. To analyze the ramping losses of NI coils, a numerical method is developed by coupling an equivalent circuit network model and a H-formulation finite element method (FEM) model. The former model is to calculate NI coil’s current distribution and turn-to-turn loss, the latter model is to calculate the magnetization loss. A test NI pancake coil is wound with REBCO tapes and the reliability of this model is validated by experiments. Then the characteristics of the NI coil’s ramping losses are studied using this coupling model. Results show that the turn-to-turn loss is much higher than the magnetization loss. The NI coil’s total ramping loss is much higher than that of its insulated counterpart, which has to be considered carefully in the design and operation of NI applications. This paper also discusses the possibility to reduce NI coil’s ramping loss by decreasing the ramping rate of power supply or increasing the coil’s turn-to-turn resistivity.
UR - http://aip.scitation.org/doi/abs/10.1063/1.4978593
UR - http://dx.doi.org/10.1063/1.4978593
U2 - 10.1063/1.4978593
DO - 10.1063/1.4978593
M3 - Article
SN - 0021-8979
VL - 121
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 11
M1 - 113903
ER -