It is observed that in a hybrid microgrid the current and frequency at a particular node changes as per the number, type of distributed generators (DGs), and grid/islanded connection of microgrid operation. So, the provision of adaptive protection should be the primary concern for updating the relay settings as per the nature of distributed generators, the distance of the fault from the point of common coupling, and the nature of the loads in the microgrid system. The novel contribution of this paper is the implementation of the fuzzy logic-based adaptive protection scheme through analysis of the change in q component and frequency of fault current considering the low X/R ratio of DGs and modes of operation at the instant of series and shunt faults in a hybrid microgrid. In addition, the fault current shared by different DGs is derived for the q component as another contribution. Also, a new relationship between the relay current settings, frequency, and q component of fault current has been identified for the above adaptive relaying. The effectiveness of the proposed adaptive protection scheme for the hybrid microgrid is verified through a simulation case study using Matlab–Simulink software.

据观察，在混合微电网中，特定节点的电流和频率会根据分布式发电机 (DG) 的数量、类型以及微电网运行的电网/孤岛连接而变化。因此，根据分布式发电机的性质、故障与公共耦合点的距离以及微电网系统中负载的性质，提供自适应保护应该是更新继电器设置的主要关注点。本文的新贡献是通过分析 q 分量和故障电流频率的变化来实现基于模糊逻辑的自适应保护方案，考虑到 DG 的低 X/R 比和串联和混合微电网中的分流故障。此外，由不同 DG 共享的故障电流是为 q 分量导出的，作为另一个贡献。此外，已经为上述自适应继电器确定了继电器电流设置、频率和故障电流 q 分量之间的新关系。通过使用 Matlab-Simulink 软件的仿真案例研究，验证了所提出的混合微电网自适应保护方案的有效性。