Albalawi Hani, Bukhari Syed Basit Ali, Alatwi Aadel Mohammed, Wadood Abdul
Renewable Energy and Environmental Technology Center, University of Tabuk, 47913, Tabuk, Saudi Arabia.
Department of Electrical Engineering, The University of Azad Jammu and Kashmir, Muzaffarabad, 13100, Pakistan.
Sci Rep. 2025 Aug 5;15(1):28478. doi: 10.1038/s41598-025-13244-4.
The integration of distributed generation (DG) into modern electric grids has garnered considerable interest due to its potential to enhance energy resiliency, reduce carbon emissions, and improve security. However, a critical challenge arises in the form of unintentional islanding. Islanding refers to a situation when DG systems, disconnected from the main network, continue supplying nearby loads. Such events pose risks to grid stability by resulting in deviations in voltage and frequency levels, equipment damage, and network safety. To address these challenges, this study introduces a novel approach for detecting islanding events in grid-tied DG systems using Wigner distribution functions and alienation index. First, a modal voltage signal is extracted from three-phase voltage measurements. Next, delta filters capture superimposed components of modal voltage. An islanding detection index (IDI) is then developed by utilising the Wigner distribution and alienation coefficient to effectively characterize islanding signatures. Finally, the IDI is evaluated against a predetermined threshold to differentiate islanding events from non-islanding conditions. Simulations are performed in MATLAB/SIMULINK on a standard IEC microgrid to validate the effectiveness of the proposed method. The results show superior performance over traditional techniques in speed, accuracy, and non-detection zones.
分布式发电（DG）接入现代电网因其在增强能源弹性、减少碳排放和提高安全性方面的潜力而备受关注。然而，无意孤岛化成为一个关键挑战。孤岛化是指DG系统在与主网络断开连接后继续为附近负载供电的情况。此类事件会导致电压和频率水平偏差、设备损坏以及网络安全问题，从而对电网稳定性构成风险。为应对这些挑战，本研究引入了一种使用维格纳分布函数和异化指数来检测并网DG系统中孤岛事件的新方法。首先，从三相电压测量中提取模态电压信号。接下来，增量滤波器捕获模态电压的叠加分量。然后，利用维格纳分布和异化系数开发孤岛检测指数（IDI），以有效表征孤岛特征。最后，将IDI与预定阈值进行比较，以区分孤岛事件和非孤岛情况。在MATLAB/SIMULINK中对标准IEC微电网进行了仿真，以验证所提方法的有效性。结果表明，该方法在速度、准确性和非检测区域方面优于传统技术。
