Voltage Sag Source Location in Distribution Networks With DGs Using Cosine Similarity

Abstract

Power quality disturbances can cause damages to the electrical network’s customers. Therefore, nowadays power quality is considered an essential issue in distribution networks. In this regard, voltage sag is of a lot of significance among power quality disturbances. The first step in the reduction of damages caused by voltage sag is to determine the location of the disturbance source. Furthermore, recent attention to distributed generation (DG) particularly in distribution networks led to the inefficiency of the previous voltage sag source location approaches. In this paper, a new method based on voltage and current measurement data is proposed, in which cosine similarity is used to locate a voltage sag source. In the proposed method, the cosine similarity sign between two data sets is used to identify the relative location of the voltage sag source. Simulation results are presented for different scenarios in the IEEE 33 bus test network. In doing so, various issues including voltage sag source location, voltage sag original type (symmetric/asymmetric short-circuits or motor starting), the fault resistance, the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x/r</i> ratio of the grid lines, DG size, DG location, measurements error, and current transformer saturation are studied in simulations. The simulation results confirm the performance of the proposed method for the voltage sag source locating. Moreover, the comparison with some previous methods shows that the proposed method gives a better response in determination of location of the voltage sags.