Determination of the relative location of voltage sag source according to event cause

Event source locating is important to improve the power quality level and to judge the responsibilities of power quality problems. One helpful way to find the location of the power quality event source is to determine the direction of event at each monitor. This paper presents a method to determine the relative location of event source that leads to voltage sag. For this, the relative location of the source is defined first. Then, line fault, induction motor starting and transformer saturation are classified as the main causes of voltage sag and their characteristics are discussed, respectively. From these investigations, the rules to determine the relative location of event source for each cause are proposed. At last, the overall algorithm to identify the relative location and the kind of event source is organized.