Abstract
The main reason for the asymmetrical modes are different terms of the phases of the electrical network. These modes arise from the asymmetry of power sources; due to unbalance operation of the electric grid elements (longitudinal asymmetry); due to significant unbalanced loads on phases (transverse asymmetry). To ensure compatibility of electrical networks and general purpose networks, consumers need to have accurate information about low-frequency conductive electromagnetic disturbances on the coefficient of voltage unbalance reverse order. Voltage negative sequence characterizes the distortions caused by the asymmetry.