基于改进单相dq变换与形态滤波的电压暂降检测方法

A detection algorithm of voltage sag based on improved single-phase dq transformation and morphological filtering

针对电压暂降特征量检测时存在的实时性差、准确度低的问题,结合数学形态学理论和d-q变换原理提出了一种基于改进单相d-q变换与形态滤波的电压暂降检测方法。研究了改进单相d-q变换算法实现原理,构造了混合形态滤波器,并给出了滤波器结构参数选择依据。仿真分析了方法在理想电压暂降波形和含谐波电压暂降波形下的检测性能,并进行了实验验证。仿真分析和实验验证结果表明运用改进单相d-q变换可以快速准确地得到暂降幅值和相位;形态滤波能够去除检测结果中非直流量,计算量小、精确度高。

Aiming at the problems of bad real time capability and low accuracy on voltage sag characteris-tic quantity detecting and combined with mathematical morphology and dq transformation, a new algo-rithm for voltage sag detection was presented, which integrates improved single-phase dq transformation with morphological filtering. The principle of improved single-phase dq transformation algorithm was stud-ied, and a mixed morphological filter was constructed with structure parameters given. The detection per-formances of the proposed method using in ideal voltage sag waveform and containing harmonic voltage sag waveform were analyzed by simulating, and the results have been verified through experiments. The re-sults of simulation analysis and experimental verification show that the amplitude and phase angle of volt-age sag can be got quickly and accurately by using improved single-phase dq transformation and mor-phological filtering is used to remove AC components which is low computational complexity and high pre-cision.