СИГНАТУРА ДВОФАЗНИХ НЕБАЛАНСНИХ ПРОВАЛІВ НАПРУГИ В ТРИФАЗНИХ ЕЛЕКТРИЧНИХ МЕРЕЖАХ

The article proposes an approach to identifying two-phase unbalanced voltage sags in a three-phase electrical network. At the first stage, by applying wavelet transform to the electrical network voltage signal, the presence of electrical energy quality distortion, its duration and the time of its beginning and end are determined. At the second stage, the signature of voltage vectors in the complex plane is analyzed using the methodology of the space vector and zero-sequence voltage. The space vector signature consists of positive and negative angular frequency vectors, and then follows an ellipse in the complex plane. It is shown that different types of sags are identified using the characteristics of the ellipse and zero-sequence voltage. The influence of the voltage dip depth on the characteristics of the space vector for voltage sags of types C, E, G is studied.