The use of distributed generation resources, in addition to considerable benefits, causes some problems in the power system. One of the most critical problems in the case of disruption is increasing short-circuit current level in grids, which leads to change the protection devices settings in the downstream and upstream grid. By using fault current limiters (FCL), short-circuit currents in grids with distributed generation can be reduced to acceptable levels, so there is no needed to change the protection relays settings of the downstream grid (including distributed generations). However, by locating the FCL in the tie-feeder, the downstream grid is not more effective than the upstream grid and thus its reliability indices also will be changed. Therefore, this paper shows that by locating the unidirectional fault current limiter (UFCL) in the tie-feeder, the necessity of changing in the relay protection settings of upstream grids is prevented. In this paper, the proposed method is implemented, and its efficiency is reported in six scenarios.

中文翻译：

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使用故障限流器减轻分布式发电对继电器协调的影响

分布式发电资源的使用，除了带来可观的收益外，还会导致电力系统出现一些问题。中断情况下最关键的问题之一是增加电网中的短路电流水平，这会导致改变下游和上游电网中的保护设备设置。通过使用故障限流器 (FCL)，分布式发电电网中的短路电流可以降低到可接受的水平，因此无需更改下游电网（包括分布式发电）的保护继电器设置。然而，通过将整柜定位在并列馈线中，下游电网并不比上游电网更有效，因此其可靠性指标也将发生变化。所以，本文表明，通过将单向故障限流器 (UFCL) 放置在联络馈线中，可以防止改变上游电网继电保护设置的必要性。在本文中，实现了所提出的方法，并在六个场景中报告了其效率。