中文摘要：

针对目前检测电压暂降的算法存在的问题,提出了一种基于求导和数字形态变换的电压暂降检测方法,即利用求导来代替αβ-dq变换法中的相位延迟并进行数字形态变换。仿真结果证明,所提方法能够高效实时准确地检测出电压暂降特征量,不仅能检测出相位跳变、减少系统延时,而且还具有很好的抗噪性,具有实际的应用意义。

英文摘要：

For the problems existing in the current algorithms for detecting voltage sag,this paper presented a detection method of voltage sag based on derivation and digital morphological transformation. It combined with morphological filter theory and used differential coefficient instead of phase delay that was employed in αβ-dq transform method for the voltage sag detection. The simulation results show that the new method can detect voltage sag characteristics effectively,in real-time and accurately. The method not only can detect the phase jump,reduce the system delay but also has a good anti-noise property. It is expected to have the practical value.