Three-phase voltage events classification algorithm based on Fortescue theorem

One of the main problems in the electrical networks is the occurrence of voltage disturbances as dips, swells and interruptions, commonly identified as events. In order to generate statisticals indexes to assess them, it is necessary to be able to detect and classify them. Three algorithms for classifying voltage events stand out from the specific bibliography. They classify voltage events correctly under ideal conditions. However, they fail under the presence of phase jumps and phase rotations, due to the impedance characteristics of the network, load and fault, and as result of the sensitivity of the fixed classification thresholds to deviations of the pre-fault voltage from the nominal value. In order to reduce these errors of classification, a new algorithm is proposed. It is demonstrated that presents an adequate performance in the classification of events affected by the disturbances previously described. Unlike the other algorithms in the bibliography, it does not use fixed thresholds, so it is better adapted to the normal changes in the pre-fault voltage produced in the network, as well as to the variations in the phase angles during the occurrence of the event.