Due to the influence of inverter control, the short-circuit current provided by distributed photovoltaics (PVs) exhibits new characteristics, such as a controlled amplitude and phase angle, resulting in the malfunction of the current protection and differential protection of distribution networks with high PV penetration. In this paper, the equivalent high-frequency impedance model (EHFIM) of PV power generation and the analysis method of a fault high-frequency superimposed network are proposed. On this basis, we analyze the fault high-frequency superimposed network of a distribution network with high PV penetration and propose a high-frequency fault analysis-based pilot protection scheme, in which the range of frequency employed for protection (FEP) is analyzed theoretically. By comparing the relationship between the high-frequency operating impedance and the high-frequency restraining impedance, the internal and external faults are identified. The proposed protection scheme has the advantages of a fast trip, low requirement for data synchronization, immunity to inverter control and the PV operation mode, and adaptability to lines with teed feeders. The experimental results show that the proposed protection scheme can accurately identify internal and external three-phase, two-phase, and two-phase grounding faults and is resistant to both fault resistance and noise interference.

中文翻译：

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基于高频故障分析的高光伏渗透率配电网先导保护方案


由于逆变器控制的影响，分布式光伏提供的短路电流呈现出幅值、相角受控等新特性，导致高光伏配电网电流保护和差动保护误动作。渗透。本文提出了光伏发电等效高频阻抗模型（EHFIM）和故障高频叠加网络的分析方法。在此基础上，对高光伏渗透率配电网的故障高频叠加网络进行了分析，提出了一种基于高频故障分析的先导保护方案，对保护频率（FEP）范围进行了理论分析。 。通过比较高频工作阻抗和高频抑制阻抗之间的关系，识别内部和外部故障。所提出的保护方案具有快速跳闸、数据同步要求低、不受逆变器控制和光伏运行模式影响以及对带有Ted馈线的线路的适应性的优点。实验结果表明，所提出的保护方案能够准确识别内部和外部三相、两相和两相接地故障，并且具有抗故障电阻和噪声干扰的能力。