基于形态滤波和Hilbert变换的电压暂降检测研究

电压暂降已成为电能质量暂态问题中最为突出的一类.针对电压暂降检测中具有的准确性低、实时性较差的缺点,提出了一种基于Hilbert变化与形态滤波相结合的暂降检测方法.研究论述了Hilbert变化用于电压暂降检测的算法基本原理,介绍了数学形态学概念,并由此基础设计了形态学滤波器,同时阐述了滤波器参数的选取方法.仿真论证了该方法在单相接地故障引起的电压暂降中的检测效果,并与单相dq变换法进行了比较.从仿真结果可以看出该方法可以更高效精确地检测到暂降的幅值以及相位.

Research on detection of voltage sag based on morphological filter and Hilbert transform

Voltage sag has become an increasingly prominent issue in power quality. In this paper, a new voltage sag detection method based on Hilbert transform and morphological filter is proposed to solve the problem of low accuracy and poor real-time performance in voltage sag detection. The basic principle of Hilbert transform for voltage sag detection is discussed. The concept of mathematical morphology is introduced, and the morphological filter is constructed based on it. The selection of filter parameters is given. The performance of this method in voltage sag caused by single-phase-to-ground fault is analyzed and compared with single-phase dq transformation method. Simulation results show that the method can detect the sag amplitude and phase more quickly and accurately.