A Resistance Sign-Based Method for Voltage Sag Source Detection

Abstract

A method to determine the origin of voltage sag disturbance is proposed in this paper. Its principle is to estimate the equivalent impedance of the nondisturbance side by utilizing the voltage and current changes caused by the disturbance. The sign of the real part of the estimated impedance can reveal if the disturbance is from upstream or downstream. The proposed method can be easily implemented into power quality meters for troubleshooting applications or into digital revenue meters to document the responsibility for disturbances. Extensive field and laboratory test results have proven the effectiveness and robustness of the proposed method.Index Terms-Least-squares method, power quality, voltage sag, voltage sag source detection.

High Frequency Impedance Based Fault Location in Distribution System With DGs

“…Unlike the conventional impedance based methods, the relationships between the changes of the system impedance (caused by different faults) and the changes of the voltages at different system nodes are used. The voltage variations (voltage sag/increase) are monitored [19][20][21][22][23][24][25][26] to locate faults. The system pre-fault and post-fault steady state voltages at different system nodes are recorded to calculate the voltage sags of different fault scenarios and a map of the voltage variations for different faults can be derived by off-line simulations.…”

Single-Point Methods for Location of Distortion, Unbalance, Voltage Fluctuation and Dips Sources in a Power System

“…[10-13,36,]), voltage dips (e.g. [17,19,22,25,26,[29][30][31]37,39]), occasionally also asymmetry. With the deregulation of power industry, utilities have become increasingly interested in quantifying the responsibilities for power quality problems.…”

Analysis of Voltage Sag Source Location Based on Wavelet-Multiresolution Method

“…There are some studies on voltage sag source location at home and abroad [1][2][3][4][5][6][7][8] : It uses disturbance power and disturbance energy to determine the sag source relative to monitoring points in [1][2][3];In [4], it judged the location from impedance and phase angle change before and after sag ,which seen from the relay installed in lines. The limitations of this method lies in relay direction errors affected by location of faults and other factors; In [5] and [6], It determined the location according to positive and negative condition of the real and imaginary parts of equivalent impedance before and after sag.…”

“…The limitations of this method lies in relay direction errors affected by location of faults and other factors; In [5] and [6], It determined the location according to positive and negative condition of the real and imaginary parts of equivalent impedance before and after sag. The difficulty is that the choice of measurement period before and after sag may affect the outcome's correctness.…”