Power swings appear as a result of sudden addition or removal of heavy loads, switching, cutoff of a parallel line, and reclosing. These swings can affect the protective zones of distance relays, causing them to malfunction and erroneously cut off healthy lines from the grid. This paper proposes a new solution for detecting power swings and preventing this malfunction based on the variance of data sampled from the current signal. The lack of any signal processing phase in the proposed solution makes it computationally light and thus suitable for implementation in distance relays. In addition, the method's performance is not affected by the presence of noise in the sampled signal. The method is able to detect power swings of stable, unstable, and multi-mode variety. In comparison with some of the latest works in the field of power swing detection as well as conventional methods, it is demonstrated that the method outperforms them in terms of response time, the ability to detect different varieties of the power swing, and the ability to detect different varieties of faults that may occur simultaneously with a power swing.

由于突然增加或移除重负载、切换、平行线路的切断和重合闸，会出现功率波动。这些波动会影响距离继电器的保护区域，导致它们发生故障并错误地将健康线路从电网中切断。本文提出了一种新的解决方案，用于检测功率波动并根据从电流信号中采样的数据的方差来防止这种故障。所提出的解决方案中没有任何信号处理阶段，这使得它的计算量很小，因此适合在距离继电器中实现。此外，该方法的性能不受采样信号中噪声的影响。该方法能够检测稳定、不稳定和多模式变化的功率摆动。