The short-circuit fault current on the dc side affects the operation safety of the multiterminal flexible HVdc (MTDC) transmission system seriously. The resistance-type superconducting fault current limiter (RSFCL) has received extensive attention in limiting the dc impact current because it has a fast response speed and zero impedance at a steady state. At present, there are so many works on the simulations of RSFCLs but the error is relatively larger, which affects the design accuracy of RSFCLs. In this article, the characteristics of dc fault current limiters are studied. The resistance and other parameters of yttrium barium copper oxide (YBCO) samples under the dc impact are measured. The equivalent heat capacity and the equivalent heat dissipation of YBCO tapes are defined and calculated to analyze the heat transfer process of YBCO tapes under the dc impact. A modeling method based on the equivalent heat parameters is obtained. In addition, the thermal balance point during the dc impact is defined by that thermal power production and heat loss of the YBCO tape are equal to identify the credible boundary of the resistance curve. Finally, the correctness of the proposed method is verified by the experimental results of fault current limiter coils and compared with the R-Q fit model. This research aids in the simulation analysis and optimization design of dc RSFCLs.

中文翻译：

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直流冲击下故障限流线圈的电阻模型

直流侧短路故障电流严重影响多端柔性高压直流(MTDC)输电系统的运行安全。电阻式超导故障限流器（RSFCL）由于响应速度快、稳态阻抗为零，在限制直流冲击电流方面受到广泛关注。目前对RSFCLs的仿真工作较多，但误差较大，影响了RSFCLs的设计精度。在本文中，研究了直流故障限流器的特性。测量了直流冲击下钇钡铜氧化物 (YBCO) 样品的电阻和其他参数。定义并计算YBCO胶带的等效热容和等效散热量，分析YBCO胶带在直流冲击下的传热过程。得到了一种基于等效热参数的建模方法。此外，直流冲击期间的热平衡点由YBCO胶带的热功率产生和热损失相等来确定电阻曲线的可信边界。最后，通过故障限流线圈的实验结果并与RQ拟合模型进行比较，验证了所提方法的正确性。本研究有助于直流 RSFCL 的仿真分析和优化设计。直流冲击期间的热平衡点由YBCO胶带的热功率产生和热损失相等来确定电阻曲线的可信边界。最后，通过故障限流线圈的实验结果并与RQ拟合模型进行比较，验证了所提方法的正确性。本研究有助于直流 RSFCL 的仿真分析和优化设计。直流冲击期间的热平衡点由YBCO胶带的热功率产生和热损失相等来确定电阻曲线的可信边界。最后，通过故障限流线圈的实验结果并与RQ拟合模型进行比较，验证了所提方法的正确性。本研究有助于直流 RSFCL 的仿真分析和优化设计。