Recently, the requirement of the electrical energy from the renewable source has been growing in the South Korea since government’s energy plan to generate the electrical power of 20% as renewable source. In addition, these renewable power plants have been constructed on not only the existing power plant’s side but also customer’s side. These changes in power distribution system cause the fault current to increase higher and to reverse the direction of the fault current. Variable countermeasures to reduce the fault current have been studied and the introduction of the superconducting fault current limiter (SFCL) in the power distribution system, one of them, has been actively reported. However, the installation of the SFCL can affect the power system protection because of the fault current’s decrease or increase, which depends on the construction of the power distribution system. Especially, the application of the SFCL in a closed-loop power distribution system can cause the delayed trip operation or the fast trip operation of the over-current relay (OCR), one of the representative protective devices widely used in a power distribution system. This change can influence on the existed protective coordination. In this paper, the OCR with voltage component, one of the methods to suppress its trip operation’s change in a power distribution system with a closed loop construction due to the application of the SFCL, was suggested and the protection coordination between the OCRs in a power distribution system with a closed loop was analyzed. It was confirmed that a simple using voltage component in the OCR could cause the trip variation of the reverse direction OCR in loop power system and it can be improved by matching the relaying voltage components.

中文翻译：

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带有 FCL 的闭环配电系统中 OCR 与电压组件的保护协调

近来，自从韩国政府的能源计划将 20% 的电力作为可再生能源发电以来，韩国对可再生能源的需求一直在增长。此外，这些可再生能源发电厂不仅建在现有发电厂一侧，而且还建在客户一侧。配电系统中的这些变化会导致故障电流升高并反转故障电流的方向。已经研究了减少故障电流的可变对策，并且在配电系统中引入超导故障限流器（SFCL），其中之一，已经积极报道。然而，SFCL的安装会因为故障电流的减少或增加而影响电力系统的保护，这取决于配电系统的建设。特别是SFCL在闭环配电系统中的应用，会引起配电系统中广泛使用的代表性保护装置之一的过电流继电器（OCR）的延迟跳闸操作或快速跳闸操作。这种变化会影响现有的保护协调。本文提出了带电压分量的 OCR 是一种抑制由于 SFCL 的应用而导致的闭环结构配电系统跳闸动作变化的方法，并提出了一个电源中 OCR 之间的保护协调。分析了具有闭环的配电系统。