Abstract Penetration of distributed generations (DGs) enable microgrid to operate in different mode such as grid-connected and islanded mode with radial and mesh topology. The fault current magnitude and direction varies according to the operating conditions which imposes serious protection challenges and may lead to protection system failure and nonselective relay operation. Thus, the impact of operating conditions on the existing overcurrent relay coordination has been extensively studied in this paper. The overcurrent relay coordination is implemented using genetic algorithm (GA) considering different topology and operating modes of the microgrid. Extensive test results indicate that the existing overcurrent relay coordination may fail during some critical operating conditions and thus, a differential relay coordination scheme is proposed which provides improved performance for microgrid operating in different modes and different network topologies with both synchronous and inverter-based DGs.

中文翻译：

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微电网运行对过流继电器协调性能的影响和差动继电器协调的评估

摘要 分布式发电（DGs）的渗透使微电网能够以不同的模式运行，例如具有径向和网状拓扑结构的并网和孤岛模式。故障电流的大小和方向根据工作条件而变化，这给保护带来了严重的挑战，并可能导致保护系统故障和非选择性继电器操作。因此，本文广泛研究了运行条件对现有过电流继电器协调的影响。考虑微电网的不同拓扑和运行模式，使用遗传算法 (GA) 实现过流继电器协调。广泛的测试结果表明，现有的过流继电器协调可能会在某些关键操作条件下失效，因此，