基于数学形态学的电压暂降扰动定位中的应用

Application of voltage sag disturbance localization based on mathematical morphology

鉴于传统的方法在定位电压暂降起止时刻存在实时性差的问题,提出了基于移相小角度的αβ-dq变换和Sobel算子相结合的单相电压暂降扰动定位的检测算法。首先,利用形态学滤波器对电压暂降信号预处理,进行移相小角度的αβ-dq变换实现直流分量的提取。然后,引入形态学Top-hat变换结合Sobel边缘检测算法,对基波电压幅值进行平方和放大变换,进一步抑制背景梯度的影响,从而实现最终的定位结果。通过不同方法对比仿真试验可知:所提方法具有计算量小、实时性强的优点,且极大加强了电压暂降扰动点的定位精度。

Aiming at the problem of poor real-time performance at the beginning and end of the positioning voltage sag that traditional method has, a detection algorithm for single-phase voltage sag disturbance localization based on the combination of αβ-dq transformation and Sobel operator at a small phase shifting angle is proposed.Firstly, voltage sag signal is preprocessed by morphological filter, and then the DC component is extracted by αβ-dq transformation with a small phase shift angle.Then, morphological Top-hat transformation and Sobel edge detection algorithm are introduced to carry out the square and amplification transformation of the amplitude of the fundamental wave voltage to further suppress the influence of the background gradient, so as to achieve the final positioning result.By comparing the simulation results with different methods, it can be seen that the proposed method has the advantages of small computation quantity and strong real-time performance, and greatly enhances the positioning precision of the voltage sag disturbance point.