This paper presents an online index for adaptive protection of microgrids concerning the low inertia concept. A three-step approach is developed to consider two offline and online environments, and the proposed scheme is designed. In Step-1, a comprehensive study of the microgrid dynamical model is investigated through two different distributed energy resources (DERs), including generator-based and inverter-based resources. In this step, based on the low-inertia concept, a dynamical model of an adaptive protection scheme is proposed through a set of non-model-based indexes. In Step-2, considering online evaluations of produced indexes, two different equations are provided in the form activation point and triggering point which the corresponding adaptive protective zones are provided. In this step, considering different operational and topological points of microgrid, the protective abilities of proposed indexes are validated and reorganized. Finally Step-3 concentrates on the ability of the proposed defensive scheme in real-time operating mode. In this step, considering different fault scenarios, the accuracy estimation and fast detection of the developed protection scheme are investigated, and the microgrid dynamic security is evaluated. Results present the effectuality of the proposed scheme to fast and secure detection of unstable scenarios using adaptive non-model-based signals concerning different system structures.

本文提出了一种基于低惯性概念的微电网自适应保护在线指标。开发了一种三步法来考虑离线和在线两种环境，并设计了所提出的方案。在步骤- 1，微电网动态模型的全面研究是通过两个不同的分布式能源（分布式能源），包括基于逆变器式发电机和基于资源的影响。本步骤中，基于低惯量概念，通过一组非基于模型的指标，提出自适应保护方案的动力学模型。在步骤 2, 考虑到生产指标的在线评价, 以激活点和触发点的形式提供了两个不同的方程, 并提供了相应的自适应保护区。在这一步中，考虑微电网不同的运行点和拓扑点，对提出的指标的保护能力进行验证和重组。最后第 3 步专注于所提出的防御方案在实时操作模式下的能力。在本步骤中，考虑不同的故障场景，研究了所开发保护方案的准确性估计和快速检测，并对微电网动态安全性进行了评估。结果表明，所提出的方案使用涉及不同系统结构的自适应非基于模型的信号来快速安全地检测不稳定场景的有效性。