Currently, much awareness is paid to the effects of smart grids on efficiency of power systems and energy districts, and the selection of suitable operating modes for equipment for transmitting electric energy. Modern intelligent networks have an impact on ensuring a stable state of power system operation modes, increasing their reliability in operation, and increasing the quality of electric energy. The article analyzes the use of intelligent electrical networks and intelligent network systems in both Western countries and the Russian Federation. Statistical data on electricity consumption and forecast values for this rate of consumption are given. In the future, until 2020-2025, there will be a gradual transition to a new type of electric grid organization - smart grids. The use of electric power systems in conjunction with innovative digital information management systems will significantly change the technical and economic characteristics of future power systems in a positive way. The comparison of technical parameters of traditional and intelligent electric networks, as well as the classification of the main groups of devices controlled (flexible) by AC power transmission systems is carried out. Systems are divided according to the principle of power regulation. Implemented projects of using flexible alternative current transmission system devices in the world are presented. As a result of the analysis, it was found that China is actively developing managed (flexible) AC power transmission systems, with a large amount of investment from the state, the volume of investment is much larger and amounts to about $ 70 billion per year.

This article is dedicated to an important problem of increasing the reliability of supporting-rod porcelain insulation at electric power substations. Porcelain insulation is installed on open switchgears (OSGs) of substations as part of the main switching equipment. Obsolescence and physical wear results in the destruction of supporting-rod porcelain insulators (SRIs), which often leads to serious consequences: shutdown of substation bus systems, emergency shutdown of substation equipment, reduction of power plant loads, as well as they pose a threat to operational personnel during operational switching. When supporting-rod insulation is replaced in due time, it significantly increases the reliability of the main substation equipment. Possible causes of failures were analysed using a graphical technique (Ishikawa diagrams). It has been established that sudden temperature changes of the ambient air are an important negative aspect, especially the transition of temperature values through 0ºC. The work represents a mathematical model of the development of microfractures in the insulation body of a ceramic insulator. The influence of external forces on the insulator leads to the appearance of additional stresses in it, to the destruction of new particles and to the sudden growth of microfractures. The article gives main SRI diagnostic techniques currently used in the electric power industry. According to statistics, it has been established that a relevant approach is the transition to digital technologies, which provides an automated information processing process without deactivating a piece of equipment. The article describes and proves that the proposed system of diagnostics of supporting-rod porcelain insulation at digital substations without deactivating a piece of equipment is a relevant area of scientific development. Within the framework of this scientific study, a patent for invention No. 2743887 dated 20 April 2020 was obtained.

The problem of reducing the quality of electricity is increasingly arising in the process of increasing energy capacities. The decrease in the quality of electricity can be caused by many different factors that manifest themselves under certain circumstances, and therefore have different solutions for their elimination. The most acute problem is the impact of the electricity quality on the energy parameters of electrical equipment and power receivers in the metallurgical industry and on the railway. The article discusses the features of calculating the asymmetry of currents in a traction AC network. The main moments of calculating the settings of balancing devices are determined. The initial calculation data for balancing devices were taken from the dynamic parameters of one of the operating modes of a power transformer TDTNZh 40 MVA, to which two single-phase loads with a capacity of 17 MVA are connected to terminals AB and 10 MVA to terminals BC. The current of the negative sequence and the coefficient of the negative sequence are calculated, and the filter compensating device is also calculated using the parameters of the balancing device. Based on the calculations, the magnitude of the negative sequence current asymmetry was established and the calculation procedure for the balancing device connected to the traction winding of the transformer with the connection group Y/Δ-11 was implemented.

The article considers a method to determine the optimal load of a power transformer. A method for estimation economic damage in case of deviation of the load factor of the transformer has been developed. According to the proposed method, the optimal load factor of the power transformer was determined according to the criterion of the minimum cost of money for the transformation of electric energy. The load level of power transformers can be estimated by two criteria, i.e., by the maximum integral value of the efficiency and by the minimum loss of funds during the transformation of electricity. According to the proposed methodology, the damage was estimated when the load factor of the transformer deviated from the optimal values. For this, the relative losses of electrical energy were calculated. The results obtained, from the point of view of energy and financial and economic efficiency, show that when the load factor is overestimated relative to the optimal values, it is much more preferable to overestimate them than to underestimate them.

The aim was to determine the reliability indicators of a power supply system using an artificial neural network model. A model for calculating technical reliability was developed using the following methods: an algorithm for calculating reliability indicators of power supply systems, the method of failure rate of a power supply system and a forecasting model using artificial neural networks. It was established that a power supply system is formed by an open radial power supply circuit. The failure rate of the power supply subsystem was determined by calculating the failure rate of i-th element of the subsystem. As a result of calculating the probability of failure-free operation of the subsystem for various conditions (5 time intervals), it was found that with an increase in the operating time from 100 to 500 h, a linear increase in the rate of system failures occurs from 0.0051 to 0.0073 1/h. A comparison of the obtained mean-to-failure values of the main and the same backup subsystem in the unloaded mode with an absolutely reliable switch (269.62 h) with the main and the same backup subsystem in the loaded mode (202.21 h) was carried out. The results differ by 67.41 h, which indicates a higher degree of reliability of the first method. The software package Prognoz_INS_2020 was developed. An acceptable accuracy of no more than 2.17% was obtained by comparing the results of the conventional calculation of the failure rate of power supply systems and using the Prognoz_INS_2020 software package. This indicates the efficiency of the proposed software package in reliability calculations at operating energy enterprises. The proposed methods for assessing technical reliability both using the conventional model and a model based on an artificial neural network made it possible to assess the state of power supply systems, which helps to prevent dangerous emergencies.