基于p-q-r变换和数学形态滤波的电压暂降检测算法

摘要

The voltage sag detection based on p-q-r theory and morphological filter is studied for DVR. A three-phase system is constructed with the single-phase voltages and its fundamental components are converted to DC components by coordinate transformation. The AC components are removed by a morphological filter and the sag magnitude and phase angle jump are then calculated. The PLL is replaced by the reference voltages to reduce the correlated delay and error. As there are mainly Boolean operations and a few addition or subtraction operations in the morphological filter,the computation is easier than that of normal low-pass filters,resulting in shorter time delay. Simulative results prove the rapidity and reliability of the proposed method.%针对适用于动态电压恢复器的电压暂降检测进行了分析研究,提出一种基于n-q-r变换和数学形态滤波的快速检测方法.利用单相电压构造三相系统,通过坐标变换将电压的基波分量转换成直流分量,通过数学形态滤波器对非直流量进行滤波,得到相应的暂降幅值和相位跳变.由于改进的方法中用参考电压代替了PLL环节,从而减少锁相过程中的延时以及误差;同时利用数学形态滤波器代替传统的低通滤波器,基于该方法的滤波主要是布尔运算和少量的加减运算,与一般低通滤波器相比,计算简单且延时短.仿真结果证明了该方法的快速性和有效性.