The main task of electric networks is providing effectively the needs of consumers in energy of the appropriate quality at minimum costs and sufficient level of reliability. This causes a constant increase in the size of the grids and the complexity of the structure. They have become the only complex for the transformation, stabilization of parameters and transport of electricity. At the same time, with the development of new technological processes, the share of asymmetric, nonlinear and dynamic consumers of electricity is continuously increasing. In practice, all this leads to the fact that in electricity networks such factors of distortion of the electricity quality as deviation, oscillation, asymmetry and non-linearity of voltage have become permanent disturbances. They significantly reduce the efficiency of both the power supply system’s themselves and consumers which are power supplied from them. In general, the principles of construction, development of modern and promising electricity networks, methods and means of controlling their regimes should be consistent with the level and pace of the overall progress of technology and technology.