LabVIEW implementation for three-phase voltage dip classification

Voltage dips are the most common voltage disturbance in electrical networks operation. A single phase dip is characterized by several amounts such as amplitude, phase shift, start point on wave and end point on wave. Given that electricity grids are three-phase grids and voltage dips can affect one, two or all three phases, researchers have proposed over time many methods of classifying them, which can be found in the literature. Generally, power quality analyzers offer a voltage dips characterization, but don't offer a voltage dip classification. In this context, the paper presents a virtual instrument, proposed by the authors, for the voltage dip classification. The procedure for voltage dip classification is first theoretically explained, and then the corresponding LabVIEW sequences are described. On the front panel of the virtual instrument is presented a list of all possible types of dips, established according to the affected phases, and the corresponding type of each voltage dip is selected from this list. For exemplification, files containing voltage dips recordings from a 220/110 kV substation are used. The paper presents the results obtained for two different voltage dip types.