Baranovska M. Promotion of work efficacy of 6-10 kV distributive nets with isolative neutral when phase is put on earth.

The object of investigation is the transient in 6-10 kV distribution networks with the insulated neutral under the line-to-ground short circuit. The investigation is aimed at reducing the overvoltage levels in the distribution networks under the complex usage of the means of their limit. The investigation methods are the approved electrical network theory, analytical methods of investigation of transient in the distribution networks under the line-to-ground short circuit and mathematical modeling methods. The novelty consists in improving of the methods of analysis of the transient in the distribution networks and getting of new analytical dependencies for identification of the overvoltage amplitudes and their intensity loss. The mathematical models taking into account the network parameters, line-to -ground circuit resistance and loading was developed and improved. The overvoltage level reducing under the complex application of the limitation means was offered. All this resulted in further developing of the transient analysis method under the line-to-ground short circuit, of the methods of overvoltage level reducing with taking into account the network parameters and the line-to-ground circuit resistance, of the methodic of calculation of the overvoltage limitation means parameters. The investigation results, the methodic of calculation of the distribution network parameters and overvoltage limitation means were assigned to the Krivbassproekt Institute and are also used by Krivirozhsky Technical University in training students. The application branch is electric power engineering.