The growth of renewable energy sources and electric infrastructure contributes to global changes in the economy and energy sector. Accounting for energy resources is becoming a key element for achieving energy sustainability and improving energy efficiency. Accurate metering systems and automation of electricity consumption control processes play a crucial role in reducing losses and increasing the stability of power grids. Electricity losses in various network segments require detailed analysis to determine effective measures to reduce them. Eliminating the "human factor" in accounting and data transmission helps to minimize errors and improve the accuracy of energy supply management.

Preventive testing of electrical equipment is a key factor in ensuring its reliable operation and preventing the occurrence of malfunctions that can lead to serious production failures. Regular insulation monitoring, verification of protective systems and measurement of key parameters make it possible to identify potential problems in a timely manner and prevent their development. Special attention is paid to the insulation condition, as it directly affects the safety and efficiency of the equipment. The use of various diagnostic techniques, such as resistance measurement, capacitance and absorption coefficient analysis, allows for a deeper understanding of the insulation condition and timely response to its deterioration. A systematic approach to diagnostics based on regular testing and the use of specialized equipment significantly reduces the risk of accidents and increases the overall efficiency of electrical equipment. This is especially important for the agricultural sector, where the smooth operation of machinery is a critical factor for successful farming.

Shutdowns of 35–110 kV power grids in most cases lead to long interruptions in power supply of quite a large number of consumers. The causes of outages are determined by the impact of a number of factors specific for each individual region. The paper analyzes the dynamics of the absolute number of lightning outages and specific outages of 35–110 kV overhead power lines. Conclusions about the causes of emergency outages are presented and recommendations on modernization of electric networks with the purpose of significant reduction of 35–110 kV overhead line outages are given.

The paper studies the actual aspects of adjustment of relay protection and automation devices (RPA), the placement of which today at power facilities is realized by using special metal cabinets. The general information and key stages of verification works during adjustment of the designated electrical equipment are presented. The peculiarities of realization of the following measures are considered: verification of compliance of the electrical connection scheme of RPA circuits with the design documents; general and functional verification, as well as adjustment of RPA organs. Important tasks of visual inspection of cabinets are listed. Particular attention is paid to the principles of measuring and correcting electrical parameters, as well as testing and checking the operation of protections. The nuances of adjustment of modern RPA cabinets based on microprocessor technologies are briefly outlined.

Nowadays, the computing power of computers is significantly superior to those that were available in the 1980s, 1990s and even in the early 2000s. The algorithms used to design power supply systems in the early 2000s differ significantly from modern ones, since the restrictions imposed on computing complexes of that time are currently irrelevant. One of these algorithms is the direct recalculation method, which allows you to calculate all possible options for laying an electrical network. This method requires significant computing resources and opens up new prospects in the field of design – "topographic maps".

Вased on the example of a power module, the calculation of the required total capacitance of a capacitor assembly, the choice of a capacitor by operating voltage, taking into account its operation at the limit of possible overheating, and the choice of the number of capacitors in the assembly, taking into account the permissible current through the capacitor, are shown. As a result of the calculations performed, the ambiguity of determining the overheating of the capacitor is shown at different values of the active loss power obtained. It is concluded that there is no simplified (without the use of similarity numbers) method for calculating the active power loss and overheating of an oxide electrolytic capacitor in relation to the considered class of thyristor power module.

The method of calculating the parameters of the control circuit in the presence of two and four bridges in the pole of the converter substation is given. The specificity of converter transformers and valves in the domestic ±750 kV control panel, which served as a prototype 30 years later for the Chinese 800 kV control panel, is noted. The noted features make it possible to recreate the implementation of domestic DC electrical equipment to increase the reliability and controllability of power supply.

The principle of operation of the automatic frequency adjustment system by regulating the voltage phase of the control generator so that it becomes equal to the frequency of the master generator is considered.

The frequency response analysis (FRA) has seen significant development and widely used application in the diagnosis of power transformer conditions in recent years. The frequency characteristics of the windings contain integral information about the electrical and mechanical state of both the windings and the magnetic core of the power transformer. Therefore, FRA has great potential for identifying damages not only in the windings but also in the magnetic system based on the analysis of frequency characteristics. The results of the conducted studies are presented, in which the emergence of a short-circuited loop with varying resistance in the magnetic system was modeled. Based on these results, characteristic frequency characteristics of the primary winding were obtained. Conclusions were drawn regarding the typical changes in frequency characteristics in the presence of a short-circuited loop and the sensitivity of the examined frequency characteristic measurement schemes.