Estimation Of Energy Losses Research Articles

How do Ritz Vectors React to the Imposed Load?

All real structures behave dynamically when loaded or displaced. Additional inertial forces are equal to the force in acceleration using Newton's second law. If the forces or the change of places are applied very slowly, the inertial forces can be ignored and a static analysis can be done. Therefore, it can be said that dynamic analysis is a simple extension of static analysis. In addition, all potential real structures have unlimited degrees of freedom. Therefore, the most critical part of structural analysis is creating a model with a limited number of degrees of freedom that has several almost massless members and several nodes, which can estimate the behavior of the structure appropriately. The mass of the structure can be concentrated in the nodes. Also, for a linear elastic system, the stiffness characteristics of the members can be estimated very accurately - according to the experimental data - although the estimation of dynamic loading, energy loss, and boundary conditions can be very difficult. Therefore, the nonlinear dynamic analysis method is usually used in theoretical studies and is not used in routine designs. So, it is a worthwhile task to propose a simple and computer method for seismic estimation of structures. For this purpose, POA has been introduced. In many cases, we can get more valuable information from POA than nonlinear dynamic analysis, this method is simple and economical and has attracted more attention nowadays.

A Novel Spring-Actuated Low-Velocity Impact Testing Setup

Evaluating the behavior of materials and their response under low-velocity dynamic impact (less than 30 m/s) is a challenging task in various industries. It requires customized test methods to replicate real-world impact scenarios and capture important material responses accurately. This study introduces a novel spring-actuated testing setup for low-velocity impact (LVI) scenarios, addressing the limitations of existing methods. The setup provides tunable parameters, including adjustable impactor mass (1 to 250 kg), velocity (0.1 to 32 m/s), and spring stiffness (100 N/m to 100 kN/m), allowing for flexible simulation of dynamic impact conditions. Validation experiments on steel plates with a support span of 800 mm and thickness of 5 mm demonstrated the system’s satisfactory accuracy in measuring impact forces (up to 714.2 N), displacements (up to 40.5 mm), and velocities. A calibration procedure is also explored to estimate energy loss using numerical modeling, further enhancing the test setup’s precision and utility. The results underline the effectiveness of the proposed experimental setup in capturing material responses during low-velocity impact events.

Indoor environmental quality assessment in passively ventilated classrooms in Germany and estimation of ventilation energy losses

In this field study we present an approach for the comprehensive and room-specific assessment of parameters with the overall aim to realize energy-efficient provision of hygienically harmless and thermally comfortable indoor environmental quality in naturally ventilated non-residential buildings. The approach is based on (i) conformity assessment of room design parameters, (ii) empirical determination of theoretically expected occupant-specific supply air flow rates and corresponding air exchange rates, (iii) experimental determination of real occupant-specific supply air flow rates and corresponding air exchange rates, (iv) measurement of indoor environmental exposure conditions of T, RH, cCO2, cPM2.5 and cTVOC, and (v) determination of real energy demands for the prevailing ventilation scheme. Underlying assessment criteria comprise the indoor environmental parameters of category II of EN 16798-1: Temperature T = 20 °C–24 °C, and relative humidity RH = 25 %–60 % as well as the guide values of the German Federal Environment Agency for cCO2cPM2.5 and cTVOC of 1000 ppm, 15 μg m−3, and 1 mg m−3, respectively.Investigation objects are six naturally ventilated classrooms of a German secondary school. Major factors influencing indoor environmental quality in these classrooms are the specific room volume per occupant and the window opening area. It is concluded that the rigorous implementation of ventilation recommendations laid down by the German Federal Environment Agency is ineffective with respect to anticipated indoor environmental parameters and inefficient with respect to ventilation energy losses on the order of about 10 kWh m−2 a−1 to 30 kWh m−2 a−1.

Utilizing deep learning towards real-time snow cover detection and energy loss estimation for solar modules

Conversion of solar energy using photovoltaic (PV) panels faces challenges due to snow accumulation on PV surface in cold regions. Despite existing methods to assess this impact, there remains a gap in real-time detection and accurate quantification of the energy loss. This study introduces a novel deep learning-based method for detecting snow coverage on PV panels for maximizing solar energy conversion. The model achieved a Dice score of 0.81 when trained on a diverse dataset of PV images, achieving a 44% improvement over conventional computer vision methods. Energy losses from snow on solar panels showed the model's predictions align closely with ground-truth data, achieving an error under 5% in snow coverage prediction. Six PV arrays were analyzed for energy loss estimation under varying snow coverage conditions. The analysis showed that the model could reliably predict energy losses due to snow accumulation with a mean error of 0.05 kWh/m2/month. The maximum energy loss was 0.23 kWh from a large PV array system covering 117 m2 area. Analysis of the impact of snow coverage duration on energy loss showed a saving potential of 0.13 kWh/m2 using timely clearing of snow coverage. This study highlights the effectiveness of CNN-based models in the early detection and measurement of snow coverage for improving the management and maintenance of PV systems.

Jet quenching of the heavy quarks in the quark-gluon plasma and the nonadditive statistics

Using the Plastino-Plastino (PP) equation, we calculate transport coefficients of the heavy-quarks traversing inside the quark-gluon plasma, and generalize their relationship with differential energy loss. The PP equation indicates anomalous diffusion of the probe particles and yields a quasi-exponential stationary distribution obtained also from the nonadditive statistics proposed by C. Tsallis. We estimate energy loss in a nonadditive quark-gluon medium, and calculate the jet quenching parameter (qˆ) for the PP dynamics. With the help of the estimate of qˆ, we calculate the nuclear suppression factor (RAA) of the heavy-quarks passing through a nonadditive quark-gluon plasma using the model proposed by Dokshitzer and Kharzeev. In many a case, the parameters in the analysis are fixed from the experimental results to minimize arbitrariness. There is a good agreement between the theoretical calculation and experimental RAA data, indicating that fast heavy-quarks may be subjected to anomalous diffusion inside the QGP.

Digitalising BIPV energy simulation: A cross tool investigation

The long-term viability of Building Integrated Photovoltaics (BIPV) as a renewable energy technology has garnered increased attention in recent discussions. However, there is currently a noticeable absence of simulation tools specific to BIPV applications that can cover the whole modelling chain. It remains unclear to what extent existing PV and BIM-based simulation tools can effectively address the complexities of BIPV projects. Therefore, this study aims to assess the process of existing simulation tools for BIPV energy simulation, three standalone PV tools (SAM, PV*SOL premium, and PVsyst), two Building Information Modelling (BIM)-based standalone PV tools (BIMsolar and Solarius PV), two plug-ins in BIM-based tools (INSIGHT for Revit, Ladybug Tools for Grasshopper/Rhinoceros 3D), and one Computer-Aided Design and Drafting (CADD) tool plugin (Skelion for Sketchup). Based on one existing building project with three different types of BIPV-installations, this study explored the capability of these eight tools in modelling/importing building geometry, selecting weather data, setting system layout and array, evaluating the solar resource, estimating energy losses, and assessing energy generation. The simulation results are compared with monitored energy yield data and presented with deviation analysis. Suggestions focus on pointing out the future development directions for BIPV digital simulation. This study offers insights and guidance for digitalising the BIPV performance simulation in the complex building design.

Undulator linear taper control at the European X-Ray Free-Electron Laser facility

Undulator tapering controls the resonance properties of the free-electron laser (FEL) amplification process. Wakefield energy losses in an undulator’s vacuum chamber are one of the factors that determine the undulator’s linear taper. While another contribution to energy losses, namely the losses due to spontaneous radiation, can be calculated analytically, estimating wakefield energy losses requires detailed knowledge of the chamber geometry and the electron beam current profile. We introduce a method for the automatic estimation of wakefield energy losses, which leverages noninvasive THz diagnostics, a current profile reconstruction algorithm enhanced with machine learning, and a recently developed analytical wakefield function for the European XFEL’s undulator beamline. The correctness of this method was validated by directly measuring wakefield-induced electron beam energy losses in the undulator section. This, in turn, enables the prediction of the optimal linear taper in the undulator. Published by the American Physical Society 2024

Methodology for selecting the method of mirror antenna protection in SHF-EHF bands from meteorological precipitations

Exhaustion of SHF band capabilities in the organization of space communication channels necessitated the transition to the lower part of the EHF band (up to 95 GHz). At the transition stage space channel antennas function in the dual frequency range. This leads to the fact that the methods of protection of ground sector mirror antennas from the impact of meteorological factors should take into account the peculiarities of propagation of millimeter-wave radio waves in the layer of precipitation that can occur in the antenna reflector. For a scientifically justified choice of the method of protection there should be a methodology that allows taking into account both electrodynamic peculiarities of propagation of radio waves of SHF and EHF ranges, and meteorological peculiarities of the antenna location. The latter determines the relevance of the proposed research topic. The objective of the article is ensuring minimum power losses and fulfillment of the rain unavailability index of the mirror antenna of the SHF-EHF wavelength bands of space communication channels by means of a reasonable choice of the method of protection against the impact of meteorological precipitation characteristic of the antenna location. It has been shown that the functioning of mirror antennas of satellite ground stations in the dual frequency range of SHF-EHF makes it obligatory to take into account the peculiarities of propagation of millimeter-wave range waves in water formations when choosing methods of protection from the effects of meteorological precipitation. The most important of these features is the increase in energy losses of millimeter-wave radio waves in the layer of water formations, the thickness of which becomes comparable to the wavelength. In addition, the methods of antenna protection should also take into account the peculiarities of digital communication lines, in particular, the fulfillment of an additional requirement (rain readiness index), assuming the restoration of the operating state of the reflector within a time of up to 10 s. The above features allowed us to formulate a criterion for a scientifically justified choice of the method of protection of the antenna of dual frequency range. The developed methodology for selecting the method of protection of the mirror antenna of the dual wavelength range is based on the theory of meteorological electromagnetism. This allows not only modeling the radio wave energy losses in the layer of precipitation taking into account strict electrodynamic models, but also assigning the parameters of the layer of water formations (thickness, type of precipitation) taking into account the climatic features of the location of the mirror antenna. Thus, the developed method provides the following algorithm for selecting the method of protection. By geographic coordinates the climatic region of antenna location is determined. For abnormal climatic regions (temperature from ‑60° to +50°, wind force up to 70 m/s, snow load up to 250 kg/m3) the application of radio transparent shelter (radome) is an alternative protection method. For other climatic regions the choice of the method of protection of the mirror antenna implies three steps: 1) estimation of energy losses in the precipitation layer on the antenna reflector at refusal of protection methods (maximum possible losses); 2) calculation of the complex criterion; 3) selection from the proposed table of the method that most fully satisfies the criterion and is the most effective for the climatic region of antenna placement. The proposed methodology allows on a scientific basis to choose the method of protection of mirror antennas of the dual frequency SHF-EHF range taking into account the meteorological features of the climatic region of its location.

Energy Efficiency Evaluation for Battery Energy Storage Stations Based on AHP-TOPSIS

The development of energy storage is a necessary support for the realization of the green energy future. At present, battery energy storage stations (BESSs) consume large amounts of energy, the energy loss relationships between various devices in a station are complex, and there is a lack of energy loss analysis and statistical methods for BESSs. It poses challenges to the further development of BESSs in the power grid. To deal with this issue, this paper establishes the energy loss indicators and proposes the energy loss evaluation methods for BESSs. The simulation results verify that the proposed method can accurately reflect the overall energy loss level of the BESSs and the proposed method of energy loss estimation and analysis can support the development of energy saving and loss reduction.

Уточнение потерь энергии в линиях электропередачи путем учета изменения сопротивления линий во времени

в работе представлен расчет потерь электрической энергии с учетом нестационарности тепловых процессов в проводах воздушных линий, возникающих из-за изменения режимных и климатических факторов (скорости и направления ветра, температуры окружающей среды). Для расчетов использовался метод, базирующийся на решении уравнения теплового баланса в нестационарном тепловом режиме проводов с возможностью расчета потерь электрической энергии, а также проводился расчет с учетом рекомендаций данных в приказе Министерства энергетики РФ от 30.12.2008 г. No326. Особенностью производимого расчета потерь электрической энергии при нестационарном режиме является применение метода, позволяющего сразу рассчитать их. Произведено сравнение полученных данных, выявлены расхождения, и представлена экономическая оценка расхождений. this study estimates the electrical power losses in overhead power lines taking into account transient thermal processes caused by changes in operating and ambient conditions (wind speed and direction, air temperature). We solved the heat balance equation for the transient thermal condition of the wires to obtain the electrical power losses as specified in the Directive No. 326 of the Russian Ministry of Energy dated December 30, 2008. The proposed method directly estimates the losses. We analyzed the results, found discrepancies and performed a feasibility study.

A Refined Model for Carbon Footprint Estimation in Electric Railway Transport

There is a plethora of methods in the global literature that can be used to measure CO2 emissions from electrified transport. But are these methods reliable, and do they offer us a true view of how much exactly of this greenhouse gas is being produced by electric rail transport? We answer this question by proposing an improved CO2 emission estimation model based on cargo transport. Unlike other works, our studies include four crucial steps: (1) estimation of energy consumption in electrified rail cargo transport; (2) estimation of energy losses in the railway traction system and high voltage transmission lines; (3) CO2 emission estimation in traditional powerhouses; and (4) determination of the intensity of the CO2 emissions from electrified rail cargo transport. Based on our method, we concluded that the intensity of CO2 depends not only on the type of fossil fuel used for energy production but also on the parameters of the cargo train, such as its length and weight or the total number of wagon axles (which depend on wagon type). The achieved intensity of CO2 emissions in electrified rail cargo transport slightly varies from those reported in the global literature. Among the most important reasons responsible for this are the conditions under which these tests were conducted. Nevertheless, our results shed new light on how CO2 should be measured. We proved that the decarbonization of electrified rail cargo transport will never be possible without infrastructure modernization. In addition, based on a case study, we also delivered knowledge on how to reduce the environmental impact of electrified rail cargo transport.

An efficient method for estimating energy losses in distribution's feeder

This paper explains a simple and efficient methodology for calculating monthly energy losses (EL) using the load loss factor technique and a representative composite load profile. One of the important benefits of the proposed work is a simpler, more efficient and less rigorous method to estimate the system-wide energy loss of an extensive distribution network with reasonable accuracy. The sum of all EL provided by each feeder section is used to calculate the total feeder EL. A base case feeder with a typical cable type and power factor is used to generate regression equations, a peak power loss function to estimate the EL. A case study is then used to show the models and techniques that have been established. The result indicates a high level of agreement with the time-series load flow simulations (smaller than 10% deviations). With this model, an approach to estimate the EL of all radial feeders of various configurations and characteristics could be extended and implemented. The spreadsheet approach is ideal for completing a quick energy audit of existing distribution feeder EL and determining the sensitivity of distribution network efficiency to changes in feeder sections and load characteristics.

An efficient method for estimating energy losses in distribution's feeder

This paper explains a simple and efficient methodology for calculating monthly energy losses (EL) using the load loss factor technique and a representative composite load profile. One of the important benefits of the proposed work is a simpler, more efficient and less rigorous method to estimate the system-wide energy loss of an extensive distribution network with reasonable accuracy. The sum of all EL provided by each feeder section is used to calculate the total feeder EL. A base case feeder with a typical cable type and power factor is used to generate regression equations, a peak power loss function to estimate the EL. A case study is then used to show the models and techniques that have been established. The result indicates a high level of agreement with the time-series load flow simulations (smaller than 10% deviations). With this model, an approach to estimate the EL of all radial feeders of various configurations and characteristics could be extended and implemented. The spreadsheet approach is ideal for completing a quick energy audit of existing distribution feeder EL and determining the sensitivity of distribution network efficiency to changes in feeder sections and load characteristics.

Competitive hierarchies in bryozoan assemblages mitigate network instability by keeping short and long feedback loops weak

Competitive hierarchies in diverse ecological communities have long been thought to lead to instability and prevent coexistence. However, system stability has never been tested, and the relation between hierarchy and instability has never been explained in complex competition networks parameterised with data from direct observation. Here we test model stability of 30 multispecies bryozoan assemblages, using estimates of energy loss from observed interference competition to parameterise both the inter- and intraspecific interactions in the competition networks. We find that all competition networks are unstable. However, instability is mitigated considerably by asymmetries in the energy loss rates brought about by hierarchies of strong and weak competitors. This asymmetric organisation results in asymmetries in the interaction strengths, which reduces instability by keeping the weight of short (positive) and longer (positive and negative) feedback loops low. Our results support the idea that interference competition leads to instability and exclusion but demonstrate that this is not because of, but despite, competitive hierarchy.

Snow Losses for Photovoltaic Systems: Validating the Marion and Townsend Models

For northern communities relying on solar photovoltaic (PV) systems to offset the cost of imported diesel fuel, there is an acute need to forecast energy losses due to snow. Two leading snow loss models, developed by Marion et al. and Townsend and Powers, are used widely in the PV industry. In order to test these models, this study compares modeled monthly and annual losses to a best-estimate reference based on PV power output and camera images from an array operating in Quebec, Canada. This study addresses two key areas: the development of an image-analysis algorithm to detect snow on a PV array and the validation of models estimating energy loss. For the PV array in this work, Townsend and Powers is a closer approximation of real annual energy losses than the Marion et al. model. However, to provide communities and PV system developers with accurate snow loss predictions, more work needs to be done to improve these models using arrays at different latitudes. The image analysis algorithm used in this work is 90% accurate in identifying snow. This leads to a difference of about 0.2% points in annual snow loss estimates when using the image analysis algorithm instead of visually inspected photos.

Estimation of Probabilistic Characteristics of Reception of Frequency-Effective Signals during Propagation along a Radio Line with Fog

A model of a radio line with fog, which is used to represent distortions of complex envelopes of digital signals because of the absorbing and dispersive properties of the propagation medium, has been considered. It is shown that with an increase in the frequency band of digital signals and with an increase in their order of manipulation (when using frequency-efficient signals), the influence of these distortions leads to energy losses in relation to propagation in free space. The quantitative estimation of energy losses for the digital signals used in applications with multi-position phase, quadrature-amplitude, and amplitude-phase manipulations and for a radio line with fog with a variation of its parameters has been carried out. It has been shown that for signals with multiposition phase and amplitude-phase manipulations (the frequency efficiency coefficient of the signals is 4 bits/s/Hz), the energy losses reach 3.5 and 1.0 dB, respectively.

Techno-Economic and Carbon Emission Assessment of a Large-Scale Floating Solar PV System for Sustainable Energy Generation in Support of Malaysia’s Renewable Energy Roadmap

Energy generation from renewable sources is a global trend due to the carbon emissions generated by fossil fuels, which cause serious harm to the ecosystem. As per the long-term goals of the ASEAN countries, the Malaysian government established a target of 31% renewable energy generation by 2025 to facilitate ongoing carbon emission reductions. To reach the goal, a large-scale solar auction is one of the most impactful initiatives among the four potential strategies taken by the government. To assist the Malaysian government’s large-scale solar policy as detailed in the national renewable energy roadmap, this article investigated the techno-economic and feasibility aspects of a 10 MW floating solar PV system at UMP Lake. The PVsyst 7.3 software was used to develop and compute energy production and loss estimation. The plant is anticipated to produce 17,960 MWh of energy annually at a levelized cost of energy of USD 0.052/kWh. The facility requires USD 8.94 million in capital costs that would be recovered within a payback period of 9.5 years from the date of operation. The plant is expected to reduce carbon emissions by 11,135.2 tons annually. The proposed facility would ensure optimal usage of UMP Lake and contribute to the Malaysian government’s efforts toward sustainable growth.

Investigation of a centrifugal pump for energy loss due to clearance thickness while pumping different viscosity oils

The clearance between the stationary volute and rotating impeller of a centrifugal pump is crucial; however, it affects the internal flow and deteriorates the pump performance. This study performed a flow investigation through a numerical simulation to understand the effect of clearance and pumping fluid viscosity under the design and off-design conditions of a centrifugal pump. Numerical simulations were conducted by solving unsteady Reynolds-averaged Navier-Stokes (URANS) equations and validated using experimental results. Five three-dimensional centrifugal pump flow domains were created, by varying the clearance thickness, and simulated with three different fluid properties. Consequently, the numerical simulation results aided in understanding the internal flow pattern and estimating energy loss due to disk friction and leakage through the clearance. It was found that the disk friction and leakage losses, which cause secondary losses in the pump, were highly affected by the fluid properties and clearance thickness. The clearance thickness drastically affected both the volumetric and hydraulic efficiencies to leakage; however, beyond a particular value, it became less significant. Furthermore, the viscous oils caused a high disk friction loss; however, the leakage loss was less affected by the clearance thickness.

ПРОБЛЕМА ОПТИМАЛЬНОСТІ АДАПТИВНИХ РАДІОТЕХНІЧНИХ СИСТЕМ В СИТУАЦІЇ З НЕКЛАСИФІКОВАНОЮ НАВЧАЛЬНОЮ ВИБІРКОЮ СПОСТЕРЕЖЕНЬ

Statistical synthesis of adaptive systems for spatiotemporal signal processing in most radio engineering problems occurs under the condition of parametric a priori uncertainty. The prospective direction of overcoming parametric a priori uncertainty is affiliated with the prior learning procedure. As a result of the training, sufficient statistics of likelihood ratios are formed, which are used in decision-making. The asymptotic optimality of adaptive systems with alternative benchmarks, one of which is peculiar to the class of radio structures with an adaptive antenna array and the other with an adaptive interference compensator, is studied subjectively with unclassified training sampling. The optimality of the system is determined by the criterion of maximum signal-to-interference ratio. The energy parameter representing the signal-to-interference ratio at the output of adaptive radio systems with a generalized reference was chosen as an indicator of optimality. As a result of the research, analytical expressions for the estimation and comparative analysis of energy losses at the output of adaptive systems with different standards under conditions of classified and unclassified learning were obtained. The invariance of the system with an adaptive antenna array to any type of training with preservation of the asymptotic properties of the radio system in the situation with a finite size of the training sample is proved. This feature is considered as a basis for factorization of the transfer function of the adaptive system. This makes it possible to form an optimal hierarchical algorithm for compensation of combined passive and active interference, as well as active interference with an arbitrary spatial power spectrum. The obligatory classification of a training sample of observations for radio engineering systems with an adaptive interference compensator under conditions of signal-interference a priori uncertainty is substantiated. Keywords: asymptotic optimality, adaptive system, alternative benchmark, unclassified training sample, correlation matrix of observations, energy index.

Development of a Superconducting Wire for the Central Solenoid of a Tokamak with Reactor Technologies (TRT)

The article presents the results of the preliminary development of a superconducting wire based on the VS type design and parallel tape packages for the central solenoid of a compact tokamak with reactor technologies (TRT). One of the main problems that must be solved for successfully implementing such projects is to develop high-current high-temperature superconducting (HTS) conductors for toroidal excitation coils and central solenoid sections. The magnetic system compactness entails the need to develop a conductor with a high engineering current density up to 90 A/mm2. The operating current in the windings should be at a level of 60 kA at 15 K in a magnetic field of 15 T. The wire in the central solenoid experiences significant mechanical loads caused by Lorentz forces. In addition, in view of a significant energy stored in the magnet, there is a need to have elements in the conductor able to perform emergency evacuation of energy with an acceptable voltage across the winding and its heating that will not entail damage to its elements. The conductor structure should have enough space to accommodate stabilizing and strengthening materials, as well as cooling channels. Two design versions of the VS type conductor based on radially arranged second-generation HTS tapes and based on parallel packages are considered. The design characteristics of the proposed conductors are analyzed for various operating modes of the tokamak electromagnetic system. The results of FEM-based calculations of the magnetic field distribution in a conductor, its current carrying capacity and energy loss estimation in a varying magnetic field are presented.