Bulletin of the Russian Academy of Sciences. Energetics

The paper demonstrates that a key element in ensuring the country's energy security is ensuring reliable fuel and energy supplies to consumers. Broader interpretations of the concept of energy security, which take into account environmental, social, and economic issues, etc., blur this crucial objective, should be considered within the context of research on other types of security, each with its own specific characteristics. It has been shown that a significant factor influencing the increasing threat of underinvestment in the energy sectors is the decline in revenues from Russian fuel and energy resource exports, with a high risk of further decline if the shadow export system is disrupted. The realization of this threat significantly increases the risk of the aging of the energy sector's fixed assets and exacerbates the problem of timely implementation of best available techniques in the energy sectors. For a comprehensive analysis of energy security issues in terms of reliable fuel and energy supply to consumers, the most effective tool should be specialized software packages, updated and updated as problems arise, such as the Intek-A software package used at the ISEM SB RAS.

The article presents a method for restoring the operating mode of energy districts containing distributed energy resources (DERs). As integral components of modern distribution networks, such energy districts significantly complicate post-fault recovery processes due to operational variability and the need to coordinate multiple distributed assets. The proposed method combines graph neural networks (GNNs) and reinforcement learning to effectively analyze the topology of distribution networks and assess the state of integrated DER-equipped energy districts. GNNs are employed to analyze network topology and real-time system states while efficiently accounting for complex interrelationships between system components, including DERs. A reinforcement learning-based agent optimizes switching decisions for circuit breakers by training on multiple scenarios and considering key aspects such as minimizing restoration time, reducing energy not supplied, and maintaining operational constraints to ensure system reliability. The approach's key advantage lies in its ability to handle multi-criteria constraints, including minimizing restoration time, reducing power losses, and maintaining voltage levels within regulatory limits. Experimental studies conducted on a test model of an energy district with heterogeneous DERs demonstrated the method's high effectiveness in restoring network operations following disturbances and failures. Significant improvement in system reliability was achieved with minimal switching operations. Moreover, the method exhibits computational efficiency by delivering solutions equivalent to exhaustive search results without exponential growth in computational complexity.

In order to increase the reliability and efficiency of a single-circuit steam-gas plant of the utilization type, it is proposed to install a two-stage intermediate steam superheater in the waste heat boiler after the high-pressure steam generation circuit for secondary superheating of the water vapor that has worked in the high- and medium-pressure cylinders of the steam turbine. In this case, the steam turbine is made three-cylinder, and in the tail section of the single-circuit waste heat boiler, a heat exchange surface of the source (or network) water heater is additionally located. The transition to a single-circuit scheme of a combined-cycle gas turbine unit simplifies the design of the waste heat boiler with a reduction in its metal consumption. As a result of the double secondary superheating of water vapor, the reliability and efficiency of the steam turbine increase due to an increase in the degree of dryness of the water vapor at the outlet of the turbine and the operability of the working fluid in its flow section. The analysis of the operation of the combined-cycle plant PGU-200 of Syzran TPP without and with the use of two-stage intermediate superheating of water vapor was performed. The study also analyzed the effect of fresh steam pressure on the main performance indicators of the combined-cycle plant when implementing the proposed method of its operation. It was found by calculation that double intermediate superheating of water vapor allows to increase the efficiency of the steam turbine by 1.7% (from 34.07 to 35.77%), due to the increase in steam operability, and the degree of dryness of water steam exhausted in the turbine from 87.835 to 98.751% compared to the base variant. At the same time, specific consumption of fuel equivalent for electric power generation by combined cycle gas turbine decreases by 1.59% (from 231.99 to 228.29 g/(kW h)).

According to government documents, local power supply in decentralized territories of the Far Eastern Federal District and the Arctic Zone of the Russian Federation is provided by 459 diesel and 12 gas-turbine and gas-piston power stations with a total installed electrical capacity of 823 MW and average level of equipment wear exceeding 50%. The use of diesel fuel, supplied through the “northern delivery”, increases the cost of electricity and causes significant damage to the northern environment through combustion emissions and the haphazard storage of empty fuel barrels. Reducing this impact is particularly urgent for the Arctic Basin, as due to climate change, air temperatures here are increasing twice as fast as the global average and may increase locally by more than 9°C by the middle of the 21st century. Given the high wind energy potential of these territories northern regions, developing the remote Arctic areas energy supply is possible through the introduction of hybrid energy complexes with adapted modular wind turbines. An adapted arctic wind turbine is a horizontal-axis unit with a 3-bladed rotor, a direct-drive connection to the generator, implemented cold-climate protection measures, a tubular steel tower, and a pile foundation with a high pile cap or a modular gravity foundation. The article considers and solves scientific and technical tasks related to substantiating the energy parameters and calculating the structural elements of wind turbines for Arctic conditions, based on a set of methods and models, including turbulent wind flow modeling considering specific climatic factors, calculation the aerodynamic, energy, and load characteristics of the rotor, finite element analysis and wind turbine digital prototype virtual testing based on aeroservothermoelastic modeling. Field studies of the energy characteristics and dynamic response of an Arctic wind turbine operating at an oil production facility in the Nenets Autonomous Okrug were conducted. The use of reverse engineering methods made it possible to obtain dependencies for the power coefficient of a commercial wind turbine.