Protection of Inverter-Based Islanded Microgrids via Synthetic Harmonic Current Pattern Injection
Protection of Inverter-Based Islanded Microgrids via Synthetic Harmonic Current Pattern Injection
复制标题
通过合成谐波电流模式注入保护基于逆变器的孤岛微电网
DOI：
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发表时间：
2021
影响因子：
4.4
通讯作者：
A. Mehrizi‐Sani
中科院分区：
文献类型：
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作者：
K. Saleh;Mahmoud A. Allam;A. Mehrizi‐Sani
由于逆变器的故障电流贡献有限，基于逆变器的孤岛微电网中的故障可能是一个艰巨的保护挑战。本文设计了一种选择性和敏感的保护方案，通过注入模式的三个合成谐波利用现有的逆变器为基础的分布式发电（IBDG）控制器的灵活性（称为注入模式[IP]）。每个继电器的测量模式（MP）是来自微电网中不同位置处的IBDG的IP的组合的结果。为了确保继电器测量正向和反向故障的不同MP，制定了一个优化模型，以设置和最小化IBDG的IP总数。提出了一种基于模式的方向性元素的基础上的余弦相似性度量之间的MP和每个中继的预定义的特征模式（CP）。CP被设置为离线作为正向故障的归一化MP。提出了一种新的方向比较继电保护方案，该方案包括主保护和远后备保护的允许越限跳闸和方向区域联锁。在PSCAD/EMTDC中的暂态研究验证了所提出的方案在各种故障和不同的微电网拓扑结构下的性能。
Faults in inverter-based islanded microgrids can be a formidable protection challenge due to the limited fault current contribution of inverters. This paper designs a selective and sensitive protection scheme by injecting a pattern of up to three synthetic harmonics utilizing the flexibility of existing inverter-based distributed generation (IBDG) controllers (called injection pattern [IP]). The measured pattern (MP) by each relay is the result of the combination of IPs from IBDGs at different locations in a microgrid. To ensure that relays measure different MPs for forward and reverse faults, an optimization model is formulated to set and minimize the total number of IPs by IBDGs. A pattern-based directional element is proposed based on the cosine similarity measure between the MP and the predefined characteristic pattern (CP) of each relay. CPs are set offline as the normalized MPs of forward faults. Moreover, a new direction-comparison relaying scheme is devised, which comprises of permissive overreaching transfer trip (POTT) and direction zone-interlocking (DZI) for primary and remote backup protection, respectively. Transient studies in PSCAD/EMTDC verify the performance of the proposed scheme under various faults and different microgrid topologies.