The protection of active distribution networks incorporating microgrids with high penetration of Distributed Energy Resources (DERs) can be challenging if traditional protective relays are used. This is mainly due to the changes in the power flow, fault current level, difficulty in protection coordination, changes in system topology, and system operating conditions. This paper proposes three new protection algorithms for active distribution networks with large penetration level of inverter-based DERs. These protection algorithms comprise of an adaptive differential protection algorithm, incremental transient energy-based directional protection, and a rate-of-change of current protection. The proposed protection algorithms were tested with a distribution network integrated with wind, solar, diesel generator, and battery storage DERs which are capable of operating in islanded mode forming local microgrids. The distribution system and the proposed protection functions modelled and simulated using the Real-Time Digital Simulator (RTDS®). The results obtained from tests validate the proposed algorithms; and their capability to correctly detect and timely isolate faults without resulting in nuisance tripping of the DERs.

如果使用传统的保护继电器，则保护包含分布式能源 (DER) 高渗透率的微电网的有源配电网络可能具有挑战性。这主要是由于潮流变化、故障电流水平、保护协调困难、系统拓扑变化和系统运行条件的变化。本文提出了三种新的保护算法，用于基于逆变器的分布式能源具有大渗透水平的有源配电网络。这些保护算法包括自适应差动保护算法、基于增量瞬态能量的方向保护和电流变化率保护。所提出的保护算法在一个集成了风能、太阳能、柴油发电机的配电网络中进行了测试，以及能够以孤岛模式运行的电池存储 DER，形成本地微电网。配电系统和提议的保护功能使用实时数字模拟器 (RTDS®)​​ 进行建模和仿真。从测试中获得的结果验证了所提出的算法；以及它们正确检测和及时隔离故障而不导致 DER 误跳闸的能力。