This paper presents online criteria of frequency stability-based controlled islanding scheme based on the density-based clustering algorithm and the system electrical distance from wide-area measuring system (WAMS) data. For this issue, at each time window, based on evaluating the correlation coefficient criteria between all two pairs of synchronous generators (SGs), the possible coherent generator groups are identified. Next, by using clustering algorithm, the identified coherent SGs are clustered and sorted through online working mode. In this case, an online index is proposed which and developed index in the form of mixed-integer linear programming (MILP) which through real-time evaluations, the system frequency stability is evaluated. In the use of MILP processes, the network electrical distance is considered as the main objective function (OF) which by solving the proposed OF through minimum criteria, proper islanding locations are identified. Finally, at the post-islanding period, a nonlinear programming (NLP) procedure is performed trough each individual islands where corresponding proper operational feasibilities are satisfied. In this case of transient stability criteria, based on the coherent SGs located at each island, the stability criteria is preserved through coherent groups as the core of islands. Also, by allocating proper load buses based on the SGs governor capacities, the islands frequency stabilities are controlled through acceptable regions. The effectiveness of the proposed scheme is carried through two IEEE 39-bus test system and Iran practical power grid. Results present the effectiveness of the proposed approach through different islanding conditions.

本文提出了基于基于密度的聚类算法和广域测量系统 (WAMS) 数据的系统电气距离的基于频率稳定性的受控孤岛方案的在线标准。对于这个问题，在每个时间窗口，基于评估所有两对同步发电机 (SG) 之间的相关系数标准，确定可能的相干发电机组。接下来，通过使用聚类算法，通过在线工作模式对识别出的相干SGs进行聚类和排序。在这种情况下，提出了一种在线指标，并以混合整数线性规划（MILP）的形式开发了指标，通过实时评估来评估系统频率稳定性。在使用 MILP 工艺时，网络电气距离被视为主要目标函数（OF），通过最小标准求解提议的OF，确定适当的孤岛位置。最后，在孤岛后时期，通过满足相应的适当操作可行性的每个单独的岛屿执行非线性规划 (NLP) 程序。在这种暂态稳定判据的情况下，基于位于每个岛的相干SGs，通过相干群作为岛的核心来保存稳定判据。此外，通过根据 SG 调速器容量分配适当的负载总线，通过可接受的区域控制孤岛频率稳定性。所提出方案的有效性通过两个IEEE 39总线测试系统和伊朗实际电网进行验证。