Optimal location and minimum number of superconducting fault current limiters for the protection of power grids
Optimal location and minimum number of superconducting fault current limiters for the protection of power grids
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DOI：
10.1016/j.ijepes.2016.11.014
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发表时间：
2017-05
影响因子：
5.2
通讯作者：
Xiuchang Zhang;H. S. Ruiz;J. Geng;T. Coombs
中科院分区：
文献类型：
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作者：
Xiuchang Zhang;H. S. Ruiz;J. Geng;T. Coombs
本文提出了一种确定多个电阻性超导故障限流器（SFCL）分配最佳策略的新方法，旨在改善标准电网的整体保护。所提出的方法允许通过温度相关的 E-J 幂律对 SFCL 的电热特性进行建模，从而直接确定 SFCL 的最佳电阻，并考虑到不同位置发生的短路事件。该材料定律基于先前的实验证据，允许在最低复杂程度内引入超导材料的磁通钉扎、磁通蠕变和磁通流动特性。因此，我们在 SFCL 的电流限制曲线中观察到独特的扭结模式，当考虑更大的电阻时，不会进一步降低故障电流的第一个峰值，从而可以明确确定最佳 SFCL 电阻。当 SFCL 的失超特性模型被简化为指数电阻时，不会观察到这种特性，尽管最后一个可以用作辅助过程来解决特定策略所需电阻值的第一次猜测，因为它需要更少的计算时间。我们还确定，对于许多研究的案例，即安装在不同位置的一个或多个SFCL之间的组合，以及位于网络中不同点的遭受故障事件的SFCL，至少其中一个SFCL的超导性能恢复时间可以持续超过5分钟，限制了该技术大规模部署的可行性。然而，通过假设SFCL的实际运行是由SC材料完全淬火时旁路开关的自动操作辅助的，我们确定标准拓扑电网整体保护的最佳策略最多需要三个SFCL，恢复时间小于几秒。这些信息对于电力系统运营商来说具有显着的价值，因为它可以建立最大投资门槛，最终有助于做出有关部署 SFCL 技术的决策。
This paper presents a novel method to determine the optimal strategy for the allocation of multiple resistive superconducting fault current limiters (SFCLs) aiming to improve the overall protection of standard power grids. The presented approach allows for the straightforward determination of the optimal resistance of the SFCL, accounting for short circuit events occurring at different locations, by modelling the electro-thermal properties of the SFCL via a temperature dependent E-J power law. This material law, based on previous experimental evidence, allows for the introduction of flux pinning, flux creep, and flux flow properties of the superconducting material within a minimum level of complexity. Thereby, we have observed a distinctive kink pattern in the current limiting profiles of the SFCLs, from which no further reduction of the first peak of the fault current is achieved when a greater resistance is considered, allowing a univocal determination of the optimum SFCL resistance. This peculiarity is not observed when the model for the quench properties of the SFCL is simplified towards an exponential resistance, although the last can be used as an auxiliary process for addressing the first guess on the resistance value required for a specific strategy, as it demands less computing time. We have also determined that for many of the cases studied, ie, for the combinations between one or more SFCLs installed at different locations, and those subjected to fault events located at different points in the network, the recovery time of the superconducting properties of at least one of the SFCLs can last for more than 5 min, constraining the feasibility of a large-scale deployment of this technology. However, by assuming that the practical operation of the SFCL is assisted by the automatic operation of a bypass switch when the SC material is fully quenched, we have determined that the optimal strategy for the overall protection of power grids of standard topology requires a maximum of three SFCLs, with recovery times of less than a few seconds. This information is of remarkable value for power system operators, as it can establish a maximum investment threshold which ultimately can facilitate making decisions regarding the deployment of SFCL technologies.