The problem of load distribution between hydraulic units of hydroelectric power plants (HPPs) is an urgent task due to the nonlinearity of the characteristics of the hydraulic turbine and the individual characteristics of power units, the operating conditions of which are often different. It is necessary to take into account the most advanced optimization methods that take into account the nonlinearity of the turbine characteristics. Methods must also take into account strict restrictions on the operating conditions of power equipment when searching for the extremum of the objective function, specified in the form of equalities and inequalities. When solving the above optimization problem, restrictions are imposed on the computing power of automated process control systems (APCS), which must operate in real time. To solve the optimization problem, the interior point method was analyzed and the Lagrange multiplier method was modified so that it could minimize the turbine flow rate and active energy losses in the windings of electric generators and transformers. The article presents the results of modeling the developed optimization algorithms and the results of full-scale testing of an automatic production control system using the described algorithms. All tests performed showed a fairly high efficiency of the proposed optimization methods under real operating conditions.

This paper examines the problem of synthesizing a control system for a buck converter designed according to the Buck converter circuit. The proposed method for synthesizing a control system regulator allows one to take into account, when designing the regulator, oscillations and significant changes in input and output voltage in the process of voltage stabilization. This is achieved through the use of linearized models of the control object in the algorithms for calculating the parameters of the control system regulators. In this work, it is proposed to use Taylor series linearization, but the results of the work make it possible to replace the calculation of this parameter with any other method. Also analyze the use of the developed continuous regulator and the converted discrete regulators obtained on its basis. Based on the work done, a generalized method for synthesizing a regulator for a step-down voltage converter in the continuous and discrete domain was obtained. These regulators have adaptability properties, which is expressed by self-adjustment of the regulator coefficients. Due to this, it is possible to use the resulting control system over a wide range of input and output voltage values of the DC voltage stabilizer.

The increase in the share of energy output from nuclear power plants and the emergence of new requirements of the system operator of the Unified Energy System (UES) of the Russian Federation raise the question of increasing the efficiency of nuclear power plants in alternating mode. At the same time, the operation of nuclear power plants is economically feasible with a maximum utilization rate of installed capacity due to significant capital investments and the low price of nuclear fuel. A possible solution to regulating the level of supplied electricity during off-peak hours of energy consumption is to direct its excess to produce hydrogen with its further sale to consumers without reducing the power of the power unit. According to the analysis, most enterprises that are potential consumers of hydrogen from nuclear power plants have their own modular installations for its production. In the work, a comparative analysis of centralized hydrogen production at nuclear power plants and hydrogen production at places of its consumption was carried out. The daily period of hydrogen production at nuclear power plants is limited to the night period, when there is an excess of generating capacity in the energy system. In this case, local hydrogen production can be carried out evenly throughout the day. This leads to an increase in the cost of hydrogen production at nuclear power plants due to a larger storage system and an increase in the number of compressor and electrolysis units. Nuclear power plants will require significant costs to transport the generated gas. At the same time, the advantage of a nuclear power plant is the cost of consumed electricity, taken at the level of the cost of its production. For industrial consumers, the electricity tariff is significantly higher. In the work, a comparative assessment of the cost of hydrogen production at nuclear power plants and at the site of its consumption was carried out taking into account a range of system conditions. A sales premium to the cost of hydrogen production at nuclear power plants was additionally adopted. Zones of competitive efficiency in the implementation of the hydrogen complex at nuclear power plants have been identified, in which the production of hydrogen at the site of its consumption requires greater costs than the purchase of commercial hydrogen from nuclear power plants. Based on the competitive range of the sales premium to the selling price of hydrogen at nuclear power plants and the accepted initial conditions, an assessment of the accumulated net present value and payback period of the hydrogen production plant was carried out during its production at nuclear power plants for sale.

The possibilities of implementing a «hydrogen transition» in the local energy sector of the Arctic are considered based on the application of the concepts of environmentally friendly technologies and socio-technological transit according to the criterion of profit maximization. The relevance of the work is due to the reform of the electric power industry, which implies a phased transition to a competitive market model, when each manufacturer will be interested in maximizing its own profit and independently determine the volume of production of electrical and thermal energy based on modern technologies. The article discusses the possibilities of using hydrogen produced from natural gas in fuel cells in decentralized electricity and heat supply systems. The conditions for the competitiveness of the new technology in comparison with centralized systems and decentralized ones based on mini-CHPs with gas turbine or gas piston engines have been determined. It has been shown that fuel cell systems using natural gas as fuel are not energy-saving technologies, but can reduce emissions of carbon dioxide and other pollutants into the environment. Massive use of fuel cells in decentralized energy supply systems is possible only if their cost is reduced to less than $100/kW.

The results of theoretical and experimental study of a transformerless diode-capacitor voltage divider for kinetic energy harvesters are presented. The influence of the number of the divider cells, cycle duration, load resistance, diode reverse capacitances and capacitances of additional capacitors on the maximum and minimum load voltage in steadystate mode is investigated. It has been found that when the load resistance increases, the voltage division coefficient doesn’t remain the same. As a result, if the divider circuit parameters change, it is necessary to re-evaluate the division coefficient. It has been established that such behavior of the divider parameters is due to the presence of the diode reverse capacitances. Analytical expressions were obtained to calculate the parameters of the studied circuits of the transformerless diode-capacitor divider, their good agreement with experimental data is shown. Thus, these expressions can be used at the preliminary design stage of systems using transformerless diode-capacitor voltage dividers. In general, the analysis carried out and the approach being developed make it possible to significantly narrow the range of searching for the necessary system parameters at the preliminary design stage and reduce the design time.

The study proposes an alternative to the classical PID controller algorithm for controlling the speed of a permanent magnets synchronous motor, called direct discontinuous control in sliding modes, based on relay controllers. Due to the advantages shown, this method is supposed to be used to control the speed of fuel cell vehicles. A mathematical description of the sliding mode method is presented, which gives an understanding of the processes occurring in the system during transient modes. Using mathematical modeling in MATLAB/Simulink, the dynamic characteristics of the transient process in terms of speed were compared for a system with classical PID controllers and a system with control in sliding modes. The system with sliding modes showed the best indicators of regulation time and response to load changes. Thus, it is concluded that the use of the sliding mode method is preferable in the tasks of speed control of fuel sell vehicles.

The main objective of this article is to formulate a modern assessment of the development of hydrogen energy storage systems and an economic assessment of the effectiveness of their use for various tasks. Using data from various current reports from global analytical agencies, a mathematical model was built to determine the cost of electricity storage – Levelized Cost of Storage (LCOS). In order to determine the sensitivity of the LCOS indicator, the dependences of the cost of storage on: installed capacity, power supply and cost of electricity were derived. According to the modeling results, optimal scenario conditions for hydrogen storage systems were determined, under which the cost of energy storage for other systems is many times higher than the cost of storage in a hydrogen energy storage system. Based on the obtained dependences of LCOS on power and energy availability, conclusions are given on the use of hydrogen storage systems for long-term seasonal energy storage and energy arbitrage in systems with renewable energy sources.

Energy transition technologies aimed at increasing energy efficiency are a tool for achieving the goals of the Paris Agreement to limit the increase in average annual temperature. To increase the efficiency of implementation of these technologies, it is necessary to forecast innovative activity in the areas of hydrogen energy, CCUS and information technology based on taking into account key influencing factors, the contribution of sectors of the classical fuel and energy complex and the level of mutual influence of countries. Based on the analysis, a forecast was made to increase the share of the sector of international vertically integrated oil companies (VIOCs) in the total number of patents in the field of hydrogen energy by 2,5 percentage points. and an increase in the share of the national vertically integrated oil company sector in the area of CCUS technologies by 10 percentage points. by 2027. It has been determined that the innovative activity of the electricity and coal industry sectors in energy transition technologies is most resistant to the influence of external geopolitical and infrastructural crises. The market for CCUS technologies is currently more susceptible to the effects of international cooperation than the market for hydrogen energy technologies. The authors show that a decrease in the level of international integration by 25 percentage points. over the past 5 years has led to a decrease in innovative activity in energy transition technologies by 15 percentage points. In order to identify international barriers to the introduction of technologies, the authors provide a comparative analysis of the level of mutual influence of countries within the framework of international economic associations using the examples of the SCO, BRICS, and MERCOSUR. The highest level of mutual influence was identified within the framework of SCO interaction. According to the analysis, the entry of new countries into BRICS in 2024 will lead to a decrease in the integral level of innovation activity by 30 percentage points. from the current value and strength of mutual influence of countries by 50 percentage points. Taking into account the identified positive relationship between revenue and innovative activity in the area of information technology, it is recommended to direct investments primarily in favor of Industry 4,0 solutions.

In spite of concerns about pollution and high operational costs, diesel engines continue to dominate local electricity generation in off-grid areas. However, there is significant untapped potential worldwide for utilizing local renewable energy sources (RES) instead of fossil fuel generation, particularly in remote regions. To address the intermittent nature of RES, energy storage systems are crucial for off-grid communities, enabling them to rely on locally collected renewable energy. This study explores various off-grid renewable power system configurations, including batteries and hydrogen as energy storage options, to determine the most economically viable setup for remote areas. The analysis includes the Nickel-Iron (Ni-Fe) battery and considers electrolysis technology for hydrogen production. Two Integrated Hybrid Renewable Energy System (IHRES) configurations are modeled and evaluated: PV/Diesel Generator (DG)/Battery (Ni-Fe) and PV/Wind Turbines (WT)/DG/Hydrogen Storage System (HSS). The study employs a cycle charging (CC) strategy. A novel optimization algorithm called Quadratic interpolation-based artificial rabbits optimization (QIARO) is introduced to optimize the sizing of system components, ensuring cost-effective and reliable fulfillment of load demands. The effectiveness of the QIARO algorithm is initially validated through a comprehensive performance assessment, comparing it with the original artificial rabbits optimization (ARO) algorithm and other established optimization techniques across 7 benchmark functions. The results demonstrate that the QIARO algorithm surpasses the ARO algorithm, as well as other optimization techniques such as beluga whale optimization (BWO), pelican optimization algorithm (POA), weighted mean of vectors (INFO), and RUN ge Kutta optimizer (RUN), in terms of convergence speed and solution quality. After validation, the proposed algorithm is applied to the Baris Oasis in New Valley, Egypt, chosen as a representative case study of insular microgrid environments. The resulting outcomes are compared with those obtained using the original ARO algorithm, further highlighting the effectiveness of the proposed approach. Using the QIARO algorithm, the PV/DG/Battery (Ni-Fe) configuration and PV/WT/DG/HSS configuration achieve optimal Life Cycle Cost values of 645,271 USD and 1,852,421 USD, respectively.

The paper presents the results of an analysis of the parameters of a series resonant converter with clamping diodes CSRC. The operating conditions of the converter imply a wide range of changes in input voltage and load power. A control system based on pulse-frequency regulation is proposed. The frequency is set based on the input voltage, output current and converter parameters. The applicability of the control method has been verified by simulation. Starting modes at maximum power and minimum input voltage are considered. The results obtained correspond to the technical specifications.