Abstract As the penetration level of the inverter interfaced distributed generators (IIDGs) increases, it is necessary to consider the effect of the IIDG connection on fault analysis in distribution networks. To extend the conventional analysis methods, this paper proposed a sequence component-based method to analyse the asymmetrical short-circuit faults. The boundary condition alternation caused by the IIDG connection was presented as well as its effect on the phase components of the feeder fault currents. Moreover, the difference between fault currents before and after IIDG connection was analysed, considering the boundary condition alternation. The fault current values obtained in network without IIDG connection were used to calculate fault currents of the feeders connected with IIDGs, which can simplify the calculation process and reduce the calculation time. The proposed method was programmed and implemented on different cases, and results were compared with the simulation and conventional analysis method. Comparisons demonstrated the improvements of the proposed method in accuracy of the results and calculation time. The new method can be conveniently integrated into software packages for power system analysis and relay protection evaluation.

中文翻译：

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逆变器接口分布式发电机配电馈线不对称故障分析

摘要 随着逆变器接口分布式发电机（IIDGs）渗透水平的提高，有必要考虑IIDG连接对配电网故障分析的影响。为了扩展传统的分析方法，本文提出了一种基于序列分量的非对称短路故障分析方法。介绍了由 IIDG 连接引起的边界条件交替及其对馈线故障电流相分量的影响。此外，考虑边界条件交替，分析了IIDG连接前后故障电流的差异。在没有IIDG连接的网络中获得的故障电流值用于计算连接IIDG的馈线的故障电流，可以简化计算过程，减少计算时间。在不同的情况下对所提出的方法进行编程和实现，并将结果与​​仿真和常规分析方法进行比较。比较证明了所提出的方法在结果的准确性和计算时间方面的改进。新方法可以方便地集成到用于电力系统分析和继电保护评估的软件包中。