基于改进同步坐标变换的电压凹陷检测方法

提出一种新的基于改进同步坐标变换的电压凹陷检测方法。该方法针对单相凹陷,只需单相电压数据,对凹陷电压及其导数进行同步坐标变换,然后再对变换的结果进行低通滤波,得到含基波幅值和相位的直流分量。该方法不需对电网电压锁相,只需两个采样点数据就可准确求出基波的幅值和相位,所检测的凹陷起始时间没有延时,截止时间误差小。该方法原理简单,计算量小,具有工程实用意义。

A Voltage Sag Detection Method Based on Improved Synchronous Reference Frame Transform

Proposes a new voltage sag detection method based on an improved synchronous reference frame transform.This method only needs single phase voltage data to monitor simple phase voltage sag.In this method voltage signal and its derivative should be through synchronous reference frame transform and a low-pass-filter to get direct component,which includes fundamental root-mean-square(RMS) and phase.The method can use two sampling points to abstract the fundamental RMS and phase without the necessity for locking vlotage phase.Furthermore,this method can monitor the start of a sag without time delay and the end of a sag with little error.This method has the advantages of simpleness and poor computational complexity,can be used to DVR(Dynamic Voltage Restorer).