应用第2代高温超导体的冷绝缘超导电缆输电导体层间均流技术

冷绝缘高温超导电缆的导电层一般设计为多层结构以满足大电流载流特性,但伴随层数的增加,超导体上的集肤效应会引起电缆输电导体各层电流分布不均匀的问题,从而造成电缆损耗增加和传输性能下降。采用基于动态惯性权重因子的粒子群优化算法,提出了电缆导体层电流层间均流优化的设计方法。应用第2代高温超导材料钇钡铜氧涂层导体,通过建立超导电缆的等效电路模型,考虑电场、磁场等约束因素,对一根1km长,110kV/3kA等级的冷绝缘高温超导电缆进行优化设计,获得了电缆本体结构参数及输电导体层和屏蔽层的电流分布。比较优化前后层电流的结果可知,优化后超导电缆各导体层电流与平均电流相比最大不平衡率小于3.5%,各屏蔽层电流达到均布,较好地实现了电缆各导体层电流均匀分布的优化目标。最后,超导模型样缆载流特性实验也验证了优化设计方法的有效性。

Current Sharing Technology in Transmission Conductors of Cold Dielectric High Temperature Superconducting Cables Using Second-generation HTS Wires

Multi-layer structure in a cold dielectric(CD) high temperature superconducting(HTS) cable has a large current carrying capability.With the increase of the number of layers,the unevenly distributed currents caused by the skin effect in each conductor’s layer will lead to the increment of the loss and a decline in transmission performance.An optimal design model for improving the current sharing among superconducting layers was proposed by using particle swarm optimization(PSO) algorithm with dynamically changing inertia weight(DCW) and was applied to design of a 1?km,110?kV/3?kA CD HTS AC power cable based on the second generation HTS YBCO tapes.Meanwhile,the configuration parameters and the currents of the conductor and the shield layers were calculated by using an equivalent circuit model of HTS cables and considering the constraint factors of the electric and magnetic field.Comparing the design results before and after optimization,we find that the maximum unbalanced rate of current in each layer is less than 3.5%,and there is a uniform current distribution among the conductor and shield layers.At last,the current test results of a demo HTS cable show the current sharing target is achieved very well,and this optimal design method is validated.