Electrical Energy Losses Research Articles

Сучасний стан та перспективи розвитку відновлюваної розподіленої генерації в Україні

The development of distributed generation in Ukraine corresponds to global trends in the energy sector. The particular relevance of distributed energy for Ukraine lies in the fact that its development contributes to reducing the costs of energy consumers, reducing the load on energy networks and losses of electrical energy, as well as improving the reliability of the energy system and energy efficiency of the economy. This article provides an overview of the main sources, technologies, and trends in the development of distributed generation (DG) in Ukraine, including stations running on biofuels (biomass and biogas), small hydroelectric power stations, as well as distributed solar and wind power plants. Various aspects related to the current state and future prospects of distributed energy in Ukraine are considered, with particular attention to barriers that impede its development. The main operating modes of distributed generation facilities are identified together with the National Energy Company of Ukraine. An analysis of the structure of distributed generation facilities by technology and power usage is carried out using statistical data. The factors that stimulate the development of distributed generation technologies are identified, and examples of successful implementation of DG facilities in Ukraine are provided. The main expected effects of implementing DG are determined, such as the adaptation of consumers to the uncertainty of the state of electricity due to the armed aggression of the Russian Federation, increasing the reliability of power supply, partial unloading of both main and distribution power lines, reducing energy losses in networks, as well as providing opportunities for communities to meet their energy needs. In addition, the development of distributed generation can contribute to increasing the level of competition in the electricity market, stimulating the review and optimization of pricing strategies. Keywords: distributed generation, RES, local networks, decentralization of energy supply.

Selectivity Control of Oxygen Reduction Reaction over Mesoporous Transition Metal Oxide Catalysts for Electrified Purification Technologies

Direct electrification of oxygen-associated reactions contributes to large-scale electrical storage and the launch of the green hydrogen economy. The design of the involved catalysts can mitigate the electrical energy losses and improve the control of the reaction products. We evaluate the effect of the interface composition of electrocatalysts on the efficiency and productivity of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), both mechanistically and at device levels. The ORR and OER were benchmarked on mesoporous nickel(II) oxide and nickel cobaltite (NiO and NiCo2O4, respectively) obtained by a facile template-free hydrothermal synthesis. Physicochemical characterization showed that both NiO and NiCo2O4 are mesoporous and have a cubic crystal structure with abundant surface hydroxyl species. NiCo2O4 showed higher electrocatalytic activity in OER and selectivity to water as the terminal product of ORR. On the contrary, ORR over NiO yielded hydroxyl radicals as products of a Fenton-like reaction of H2O2. The product selectivity in ORR was used to construct two electrolyzers for electrified purification of oxygen and generation of hydroxyl radicals.

Comparative Analysis and Models for Losses in Electrical Energy in Low Voltage Devices

Electrical energy losses in low-voltage devices can have a significant impact on the overall efficiency of an electrical system. In this research, a comprehensive comparative analysis of losses in electrical energy in low-voltage devices, including transformers, cables, and switchgear was presented. Experiments to measure the losses under varying operating conditions, such as loads, ambient temperatures, and frequencies were conducted. The data collected from the experiments were then analyzed to identify the major contributors to losses in each device with models for these devices to predict the losses accurately. The models were based on analytical and empirical approaches, considering various factors such as size, insulation type, and operating conditions. The models were validated using the data collected from the experiments, and the results showed good agreement between the predicted and measured losses. The findings show that losses in low-voltage devices depend on various factors and can be significant. Transformers losses due to hysteresis and eddy currents were found to be effective at high loads. In cables, losses were higher at higher frequencies due to skin and proximity effects. In switchgear, losses were dependent on the type of switch used. The models developed in this study can help in identifying the significant contributors to losses and predicting the overall efficiency of an electrical system. The results of this study can be used in the design and optimization of low-voltage devices to improve their efficiency and reduce energy losses which can lead to significant savings in energy costs and improve the overall sustainability of electrical systems.

New Approach to Evaluate the Energy Efficiency of Overhead Power Transmission Lines: Results of Theoretical and Experimental Research

This article describes a new approach to evaluating energy efficiency of overhead power transmission lines which is based on power transmission line losses calculation taking into account induction currents and heating in the supporting elements. We present the results of theoretical and experimental research of induction currents and heating evaluation in pylons of the overhead power transmission line. To find the flux linkage for induction currents, calculations using the Poisson equation for vector magnetic potential were carried out. The limiting values of induction currents and heating temperature are estimated using a graphical approach. The analysis of the power losses balance for a 500-kV power transmission line demonstrates considerable energy-saving benefits. The update of the previous conference paper is implying to compare energy efficiency of the overhead power transmission line for thermal and electric energy losses associated with induced currents and to conclude about their interchangeability. Additionally, it is resumed which using technical assumptions in the study. The research work might be of interest for design and modernization of overhead power transmission lines.

Analysis of Maintenance Optimization on Medium Voltage Overhead Lines (SUTM) in Reducing Energy Not Supplied (ENS) at PT. PLN (Persero) ULP Tarakan

The background of this research is an analysis of equipment disturbances that occur in distributing electrical energy. The disturbance is a blackout. Power outages cause a decrease in the continuity of service to customers and result in a lot of loss of electrical energy that is not distributed to customers. The research objectives are to find out the optimization technique of distribution network maintenance, how to reduce the value of energy not supplied (ENS), find out the losses due to ENS, and find out the total electrical energy distributed after preventive maintenance is carried out. This research uses a preventive maintenance method, which is maintenance that can prevent unexpected damage to distribution system networks and equipment. This research optimized preventive maintenance actions by reducing disturbances after preventive maintenance from 7 disturbances in February to 2 disturbances in March. Before preventive maintenance, the loss due to ENS amounted to Rp. 36,192,017.626, and the total electrical energy not distributed was 25,025.76 kWh. After preventive maintenance, there was a significant decrease in the total loss due to ENS of Rp. 953,516,447, and the amount of electrical energy not distributed was 659.28 kWh. This research can increase maintenance efficiency due to electrical energy losses by 97.36% at the time interval when this research data is managed when data collection is carried out in the field.

АНАЛИЗ ГРАФИКОВ ПОТРЕБЛЕНИЯ ТОКА НАСОСОМ И ПРИЧИН УТЕЧКИ ЖИДКОСТИ НА ОБЪЕКТАХ ВОДОСНАБЖЕНИЯ СЕЛЬСКИХ НАСЕЛЁННЫХ ПУНКТОВ

The water supply system with a frequency converter device, used in rural settlements located on the territory of the Chuvash Republic and Nizhny Novgorod region, does not always detect the fact of fluid leakage, which entails inevitable losses of electrical energy. This significantly increases the loss of raw materials and the likelihood of draining the well. It is possible to determine a leak in such water supply systems by digitizing the operating parameters of a borehole pump and transmitting this information using the OwenCloud cloud service developed by OWEN. The purpose of the research is to determine the leakage of liquid in the water supply system of rural settlements based on indirect observation and comparative analysis of the total pump operation time per day. The studies were carried out on working days from February 3 to February 9 and during November 1, 2022. For digitization, a PM210 network gateway was used, which transmitted the operation parameters of the frequency converter (the existing control station) via the RS-485 interface, and then to the cloud environment using SIM cards. The digitized data from the cloud environment was processed in the application program according to a given algorithm with simple logic and the total operating time of the pump per day was determined. Based on these calculations, the presence of a fluid leak in the water supply system was established. Determination of the total pump operation time per day by digitizing and analyzing current consumption indicators will significantly speed up the response time to an emergency situation in the water supply system.

Operational Identification of Resistances of Wires of 380 V Distribution Networks by Automated Accounting Systems

Four-wire distribution electrical networks of 0.4 kV equipped with automated systems of electrical energy accounting are considered. The problem of identifying the resistances of the wires of the distribution network is solved on the basis of the effective values of voltages and currents, as well as of their phase shift angles obtained by the accounting system in the power supply node of the network and from its subscribers for the selected observation intervals. A brief analysis of the known methods and technologies used in this area of research is carried out. The importance of the formulated problem for applied problems, such as control and diagnostics of electrical energy losses, as well as the technical condition of the network, is noted. A method (algorithm) is proposed that allows determining unknown, unequal complex resistances of inter-subscriber sections of the distribution network. In these resistances, the reactive components are considered equal within the inter-subscriber section; the active components differ due to the influence of unequal flowing currents and/or weather factors. At the same time, data from two different network operating modes are required, which are selected based on the analysis of the dynamics of changes of supply currents and/or voltages by the accounting system device connected to the power supply node. Considering that the active resistances of the wires must remain unchanged, the mode that is used for calculations is the one that is before the change in power consumption in the network and the next one immediately (about 0.1 s) after it. An example of a calculation that demonstrates the reliability of the proposed equations of the method that has been developed on a simulated distribution network is given. The research results are focused on the improvement of automated accounting systems and the implementation of their new functions that elevate the reliability of distribution networks, as well as allowing for the rapid identification of non-technical losses of electrical energy.

Intelligent algorithm-based efficient planning of electric vehicle charging station: A case study of metropolitan city of India

Electric vehicles are gaining popularity and going to become the mainstream mode of transportation in urban and rural areas not only in India but globally in the next few years. In the adoption of electric vehicles, there are certain issues like proper charging infrastructure, charging time etc. and out of these the sizing and siting of the charging station particularly in urban areas where the cost of land and location plays an important role. Thus, it is important that the charging station location should be easily accessible for the electric vehicle users and cost effective as well. This paper presents an intelligent algorithm based efficient planning of electric vehicle charging station considering geographical information and road network. The cost function has considered such as investment cost, charging station electrification cost, electric vehicle energy loss cost and travel time cost. An intelligent algorithm-based approach is employed to solve the planning problem of electric vehicle charging stations. Further, the impact on reliability of the grid is also evaluated by determining the charging cost loss on each considered location. The result shows that the applied method provides better optimized solutions which are beneficial for electric vehicles users, charging station operator and utility grid.

Influences of Metal Core and Carbon Shell on the Microwave Absorption Performance of Cu-C Core-Shell Nanoparticles.

Metal-C core-shell nanoparticles have been recently demonstrated to be promising candidates for microwave absorption applications. However, the underlying absorption mechanism, such as the contributions of the metal cores and C shells on their absorption performance, remains far from clear due to the complicated interfaces and synergetic effects between metal cores and C shells, as well as the significant challenges in the preparation of samples with well-defined comparability. In this study, Cu-C core-shell nanoparticles and their derivatives, i.e., bare Cu and hollow C nanoparticles, were synthesized for a comparative study on their microwave absorption properties. Electric energy loss models of the three samples were established, and based on these models, the comparative study suggested that the polarization loss could be significantly improved by C shells, and Cu cores had negligible influences on the conduction loss of Cu-C core-shell nanoparticles. The interface between C shells and Cu cores tuned the conduction loss and polarization loss to establish improved impedance matching and achieve optimal microwave absorption performances. A wide effective bandwidth of 5.4 GHz and a low reflection loss of -42.6 dB were achieved for Cu-C core-shell nanoparticles. This work provides new insights into how metal nanocores and C nanoshells affect the microwave absorption of core-shell nanostructures from experimental and theoretical points of view, which has reference values for the construction of highly efficient metal-C-based absorbers.

Optimal dynamic regulation with asymmetric information in continuous time: The case of electric power

<p>In this article, we analyze the mechanism design for the remuneration to the reduction of energy losses of a natural monopoly through a dynamic principal-agent model in continuous time. The objective of this research is to characterize the optimal regulation that induces reductions in electrical energy losses. In our methodology, we use a differential equation, its HJB representation, and an exponential utility function. The results suggest that the optimal contract is based on the agent's continuation value as a state variable. The article contributes to the analysis of control problems in conditions of incomplete information and incorporates information asymmetries and incentives in regulation. Among the future lines of research are the application of the model to specific energy markets and the empirical evaluation of the effectiveness of the proposed regulation.</p>

Optimal Allocation of PV-STATCOM Devices in Distribution Systems for Energy Losses Minimization and Voltage Profile Improvement via Hunter-Prey-Based Algorithm

Incorporating photovoltaic (PV) inverters in power distribution systems via static synchronous compensators (PV-STATCOM) during the nighttime has lately been described as a solution to improve network performance. Hunter prey optimization (HPO) is introduced in this study for efficient PV-STATCOM device allocation in distribution systems. HPO generates numerous scenarios for how animals could act when hunting, some of which have been expanded into stochastic optimization. The PV-STATCOM device allocation issue in distribution networks is structured to simultaneously minimize the electrical energy losses and improve the voltage profile while accounting for variable 24 h loadings. The impacts of varying the number of installed PV-STATCOM devices are investigated in distribution systems. It is tested on two IEEE 33-node and 69-node distribution networks. The effectiveness of the proposed HPO is demonstrated in comparison to the differential evolution (DE) algorithm, particle swarm optimization (PSO), artificial rabbits algorithm (ARA), and golden search optimizer (GSO). The simulation results demonstrate the efficiency of the proposed HPO in adequately allocating the PV-STATCOM devices in distribution systems. For the IEEE 33-node distribution network, the energy losses are considerably decreased by 57.77%, and the voltages variance sum is significantly reduced by 42.84%. The energy losses in the IEEE 69-node distribution network decreased by 57.89%, while voltage variations are reduced by 44.69%. Additionally, the suggested HPO is highly consistent than the DE, PSO, ARA, and GSO. Furthermore, throughout the day, the voltage profile at all distribution nodes surpasses the minimum requirement of 95%.

DETERMINATION OF ELECTRICAL LOSSES BASED ON NODAL ELECTRICAL LOAD FORECASTS

This study proposed the use of forecasting methods based on artificial neural networks for calculating and forecasting energy losses. The calculation of energy losses was performed on the CIGRE test network. Several approaches were developed to determine energy losses: prediction of electrical energy losses using artificial neural networks, and calculation of losses using nodal load prediction based on artificial neural networks, which were compared with the classical method of calculating losses based on summer and winter peak load coefficients. Depending on forecasting problems, when using artificial neural networks, the amount of electrical energy losses in distribution networks decreased by three times compared to the calculation of losses using coefficients.

Mechanism and optimum pressure for sliding-mode nanogenerator

Abstract Triboelectric nanogenerator has extensive applicability because of its capability of harvesting mechanical energy and flexible working modes. To research the optimum pressure and improve the recovered energy of the sliding-mode triboelectric nanogenerator, a contact model of the Al/PTFE tribo-pair is studied by ab initio calculation and finite element simulation. The F-atom of PTFE is proved to be the electron accepter and the charges transferred can be predicted by Bader charge analysis. The mathematical relation between interfacial distance, charges transferred and contact pressure can be fitted. By Gauss’s law, the electric field is simulated and the regeneration energy of the sliding-mode triboelectric nanogenerator can be evaluated by the total electric energy and friction loss. Finally, an optimum pressure can be set to the upper or lower limit of working pressure corresponding to larger recovered energy. And less friction coefficient and larger contact area are also effective methods for recovering energy.

Impact of climate change on electrical energy losses in electrical networks

One of the global problems in the world is greenhouse gas emission. There are several reasons for this problem, one of which is electricity. This article provides a brief summary of the current state of electricity waste and analyzes the impact of electricity waste on greenhouse gas emissions, as well as ways to reduce greenhouse gas emissions from the point of view of electricity generation. The situation of greenhouse gas emission in the territory of Uzbekistan and how much of it corresponds to the share of electricity losses is shown.

Effect of nickel doping on the spectral sensitivity of silicon solar cells

In the modern industrial production of solar cells (SC), there is a growing trend to utilize “solar silicon” as the base material due to its cost-effectiveness. However, solar silicon possesses a drawback - it has a shorter lifetime of minority charge carriers (MCC), making it challenging to achieve high efficiency in solar cells. To address this limitation and improve the efficiency of solar cells based on “solar silicon,” two key objectives need to be met. Firstly, it is essential to increase the lifetime of photogenerated charge carriers. Secondly, there is a need to minimize both optical and electrical energy losses. To achieve an increase in the lifetime of minority charge carriers in SCs, a process called gettering can be employed. This process involves utilizing clusters of nickel atoms to trap uncontrolled impurity atoms. The paper presents the results of a study on the additional doping of silicon solar cells with nickel atoms, for factors affecting the long-wave and short-wave efficiency. Nickel doping has been shown to increase the efficiency of solar cells. It is determined that in the visible region of the spectrum the spectral sensitivity of a silicon solar cell doped with nickel is higher up to 25÷35% due to a decrease in surface recombination. Technological recommendations for nickel doping of single-crystal silicon solar cells are proposed to be combined without significant changes with the standard technological process for manufacturing solar cells.

Снижение потерь электрической энергии при передаче и распределении по электрическим сетям – приоритетное направление в цифровизации электроэнергетики, построении цифровой экономики Российской Федерации

The problem of reducing losses of electric energy during transmission and distribution through electric networks is one of the key tasks for most electric grid companies in Russia. The task of developing remote control technologies has actually been set by the Government to all subjects of the electric power industry in the regions of Russia. The article discusses the issues of the introduction of IT technologies as measures to reduce the loss of electrical energy during its transmission over networks. Proposals have been developed on the organizational, investment and economic components of creating electric systems with an intelligent network in our country.

Потери электрической энергии в электрических сетях

This article discusses the relevance of reducing electrical energy losses. The actual values and plans for reducing electric energy losses in PJSC «Rosseti» and the main branches of PJSC «Rosseti Siberia» are given. The existing standards of losses in electrical networks of different voltage levels are presented. Possible ways of reducing electricity losses to achieve the targets set by the «Energy Strategy of the Russian Federation for the period up to 2035» are considered.

Визначення оптимальної точки приєднання сонячної електростанції до електричної мережі методом комп’ютерного імітаційного моделювання

The purpose of this study is to minimize the negative impact of the solar power plant on the value of the steady voltage deviation and the level of electricity losses by determining the optimal place for its connection to the distribution network. Currently, quite a large number of methods of optimal placement of renewable sources of electricity in electrical networks have been developed. However, most of them either do not fully take into account the multifunctional influence of renewable energy sources on the parameters of the electric network regime, or are quite difficult to use. In order to solve the problem of optimal placement of renewable sources of electricity in electric networks, it is proposed to use the method of computer simulation modeling. The essence of this method is to determine the optimal place for connecting a renewable energy source to the electrical network based on the analysis of the results of computer simulation modeling of network mode parameters. This approach is the most acceptable in the case of connecting a solar power plant of average power to the electrical network of an industrial enterprise. The developed computer simulation model of a distribution electric network with a solar power plant allows for the research of network mode parameters, including the determination of the level of active power loss in network elements and the level of steady voltage deviation. The specified computer simulation models of the distribution electric network with a solar power plant made it possible to determine the optimal place for connecting the solar power plant based on the values of power losses in the elements of the electric network at the level of the established voltage deviation. The results of computer modeling of an electrical network with a solar power plant confirmed the need to take into account not only the values of the established voltage deviation, but also the amount of electrical energy losses in the network elements in the process of choosing a place to install a solar power plant. The results of the research can be used in solving the problems of determining the place of connection of a medium-power solar power plant to the electrical network of an industrial enterprise.

МОДЕРНИЗАЦИЯ ТЕХНОЛОГИЧЕСКИХ ПРОЦЕССОВ ИЗГОТОВЛЕНИЯ АЛКОЗОЛЯ WO3

Alkosol WO3 is used for the production of functional nanocoatings that exhibit electrochromic effect. These nanocoatings have a wide range of applications, but the most promising and economically feasible is their use in the structure of architectural "smart" windows to regulate the passing light and heat flows. Practical application of electrochromic windows will allow to reduce electric energy losses for heating and cooling of buildings and vehicles up to 40%. This article is devoted to the description of the developed technological approaches for the production of WO3 alcosol by the peroxide method. Modernization of the technological process of manufacturing this material made it possible to minimize the formation of a side insoluble crystalline phase of H2WO5, to automate the process of polycondensation of peroxotungstic acid, to obtain a WO3•nH2O2•mH2O hydrogel of a uniform composition, and to accelerate the dissolution of the hydrogel in ethanol from 12 hours to 5 minutes. The total time of all stages of the technological process for the production of alcosol WO3 was reduced from 3 days to 8 hours.

APPLICATION OF INDICATIVE QUALITY INDICATOR IN DYNAMIC MANAGEMENT OF THE TOPOLOGY OF A DISTRIBUTION NETWORK WITH LOCAL ENERGY SOURCES WITH THE PURPOSE OF MINIMIZING ENERGY LOSSES

In practically all countries, a significant part of distribution electric networks is operated in an open mode. Therefore, the task of choosing the optimal topology of the electrical network remains relevant and popular among researchers. To date, many ways of solving this problem have been proposed, which have been reflected in hundreds of publications. To achieve the goal of forming the optimal topology of the electric network, various optimization methods are used, the problem is also solved in both single-criteria and multi-criteria formulations. In this article, a bibliographic analysis is carried out and the use of an indicative qualitative indicator is proposed for finding the optimal topology of the distribution electric network in real time, which makes it possible to minimize the loss of active energy. Currently, this is relevant due to the growth of load heterogeneity and the increase in the share of local energy sources in the distribution networks of our country. These factors form flow distributions daily, which in most cases will not coincide with the mode for which the appropriate network configuration was chosen, which in turn leads to an increase in electrical energy losses. The effect of the proposed approach depends on the proper level of technical and information support of the network, especially since most of the equipment of distribution electric networks has exhausted its physical resource. The use of an indicative qualitative indicator is envisaged in distribution networks equipped with modern switching devices with the possibility of remote control and the presence of systematic measurements of the mode parameters of the network. Based on the obtained research results, it can be concluded that the developed indicative indicator is successfully used in solving the problems of finding the optimal network topology in real time, which makes it possible to achieve significant results. additional reduction of active energy losses.