PJSC “Rosseti” is forced to find new ways of getting additional income. It’s caused by the insufficient financing of network. But a lot of known and supported by network organizations initiatives are leading to the increase of network component in electricity cost for consumers. By the way the new subject, called demand side response aggregator in the UPS, is appeared in power engineering. This problem can be partially solved by the large regional network companies in case of them being an aggregator. At the same time, the efficiency of the aggregator function increases in case of using local power systems as a subject of the retail market as a regulatory resource. It’ll let to avoid the decrease of the power consumption and transmitted power volume, to increase the reliability and the quality of power supply due to reduce of power losses in network. It’s obvious, that the appropriate automation is needed as an element of the digital transformation of the electric network.

Abstract-Reliability of the power system depends on coordination and coherence of continuous processes of production, transmission, distribution and consumption of electric energy. It is offered to consider a power supply system of Russia as a four-level hierarchical system due to the terms of uninterrupted operation of power supplies. For each hierarchical level, there is a system of indexes, reflecting the role of the backbone, transmission and distribution networks. The authors offer to calculate reliability indexes of power supply -regional's group supply points, district centers of supply, local supply points and end-consumers. Indexes cover structural, object and regime parameters of an electrical network. This approach makes it possible to determine bottlenecks, to select and to justify the ways and means of improving the power system reliability without reducing their efficiency.Keywords-reliability; system; index; indicator; power supply I. SITUATION ANALYSIS AND PROBLEM DEFINITIONIt is known that a combination of reliability and profitability forms efficiency of a power supply system. Therefore, the efficiency index, reflecting usefulness of a power system, can be determined by the known function of Cobb -Douglas: The index of profitability I e raises in case of the reduction of costs of production, transmission and distribution of electricity, and the index of reliability I r increases with the reduction of depth, frequency and duration of switch-offs and the imposed restrictions for a power consumption. The ratio of n and m reflects the value of each of two properties. Their choice defines priorities of development of power supply systems. For example, for Soviet period, m≫n ratio was characteristic, and the searching of the way to change the situation was the purpose of the market reform, undertaken in power industry.Obviously, increasing I r , which demands certain expenses, leads at the same time to reducing I e . However, in Russia a decrease of both profitability and reliability of power supply is observed. Currently, a constant growth of electricity costs takes place and, regarding the reliability; annually over 24 thousand failures occur on power generation facilities, 700 of them are considered as serious, and more than 50 -have severe consequences [1].In market relations, in countries with economic competition of power industry subjects, the level of power supply reliability is strictly watched. It allows deriving system effect, which means a profitability increase without a reliability decrease. Interconnection of separate regional power systems into the United Power System (UPS) is the most common way to gain the system effect. To provide system interconnection in Europe and the USA, trunk lines on a direct current are widely used, while in Russia it was carried out in extra high voltage AC lines.

The reason for the appearance of the first distributed generation in Russia was the high requirements to the reliability of power supply to power consumers of a special group of the first category of reliability. Diesel generating units were used to ensure uninterrupted operation. High costs for technological connection of consumers of the 1st and 2nd categories of reliability have strengthened the tendency to install a backup energy source in the enterprises' own power supply systems. However, setting reserves leads to a decrease in economic efficiency. There are additional costs for maintaining the reserve in a working condition. As a result, enterprises transfer the backup units to the mode of the main power source, and that of the backup function to the centralized power supply system. The creation of such industrial MiniGrid operating in a mode without power supply to the grid increases the cost of electricity for other consumers. Besides, with the departure of industrial enterprises from the centralized power supply, the share of communal and non-industrial consumers is growing. This requires an increase in the manoeuvrability of energy sources. The creation of balanced Energy Cells for energy supply to the population and small and medium-sized businesses that provide services to the population is not accompanied by the negative effects indicated above. In Russia, there are isolated examples of such systems, similarly operating in a mode without supplying power to the grid. Changes are needed to allow active consumers to supply excess capacity to the grid during peak hours in the UES of Russia, for which the grid companies need to be allowed to operate at least in a mode without supplying power to the grid, which will not lead to a decrease in grid companies' revenues from electricity transmission services. The introduction of these changes does not only lead not only to an increase in the reliability of power supply but also to an increase in the economic efficiency of the UES, which will reduce the price of electricity.

The Russian energy industry today needs an “energy transition”. The key link is the Regional Electric Network Companies as the basis of regional power supply system. There are significant changes in the industry, such as changes in legislation, the emergence of new requirements, changes in the regional fuel landscape. The mass appearance of distributed generation as the basis of local power systems has a great influence on the changes. This has led to new functions for Regional Electric Network Companies. The paper studies the effect of local power systems integration on the expansion of the functions performed by distribution network. Particular attention is paid to demand management for electricity; mutual reservation, multi-agent voltage regulation, functions of local energy systems integration with distribution networks.

The article is devoted to the study of the influence of regime restrictions on the functional reliability of distribution networks of 0.4-10 kV. This level of the network is largely determining the values of indicative indicators of reliability of power supply. In the work, by the example of the analysis of the reliability of power supply of two energy regions, the significance of the influence of the regime factor on the uninterrupted power supply is proved. Due to the complexity of the topology and the variability of the flow distribution, it is proposed to use the decomposition method for calculating the reliability and recoverability of network nodes. The expediency of calculating indicative indicators of the reliability of electricity supply at the stage of network design is shown, since today, in Russia, the economic efficiency of the functioning of territorial network companies is largely determined by the level of reliability due to the existing relationship between reliability indicators and the tariff for the transmission of electric energy.