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Energies
Volume 16
Issue 9
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Energies, Volume 16, Issue 9 (May-1 2023) – 360 articles

Cover Story (view full-size image): The development of electric vehicles demands ever-better performance and efficiency from storage systems. Li-ion batteries suffer when they are subjected to high discharge and charge currents, both in terms of heat management and life cycles. In this study, the aim is to analyse the benefits achievable in a lithium battery storage system by placing a li-ion battery branch in parallel with a branch of electrostatic double-layer ultracapacitors. The configuration analysed involves the direct coupling of the two branches without the use of a DC/DC converter. The experimental results confirm the performance and efficiency of the solution, showing great increases in the C-rate charge and discharge of the storage system, and less electrical and thermal stress on the li-ion battery branch, thereby bringing benefits to the life cycle of the storage system. View this paper
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18 pages, 4901 KiB  
Article
Modeling and Harmonic Analysis of a Fractional-Order Zeta Converter
by Lingling Xie and Di Wan
Energies 2023, 16(9), 3969; https://doi.org/10.3390/en16093969 - 08 May 2023
Cited by 1 | Viewed by 1142
Abstract
The Zeta converter is an essential and widely used high-order converter. The current modeling studies on Zeta converters are based on the model that devices, such as capacitors and inductors, are of integer order. For this reason, this paper takes the Zeta converter [...] Read more.
The Zeta converter is an essential and widely used high-order converter. The current modeling studies on Zeta converters are based on the model that devices, such as capacitors and inductors, are of integer order. For this reason, this paper takes the Zeta converter as the research object and conducts an in-depth study on its fractional-order modeling. However, the existing modeling and analysis methods have high computational complexity, the analytical solutions of system variables are tedious, and it is difficult to describe the ripple changes of state variables. This paper combines the principle of harmonic balance with the equivalent small parameter method (ESPM); the approximate analytic steady-state solution of the state variable can be obtained in only three iterative steps in the whole solving process. The DC components and ripples of the state variables obtained by the proposed method were compared with those obtained by the Oustaloup’s filter-based approximation method; the symbolic period results obtained by ESPM had sufficient precision because they included more combinations of higher harmonics. Finally, the influence of fractional order on harmonics were analyzed. The obtained results show that the proposed method has the advantage of being less computational and easily describing changes in the ripple of the state variables. The simulation results are provided for validity of the theoretical analysis. Full article
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44 pages, 14103 KiB  
Review
A Review on Flame Stabilization Technologies for UAV Engine Micro-Meso Scale Combustors: Progress and Challenges
by Gurunadh Velidi and Chun Sang Yoo
Energies 2023, 16(9), 3968; https://doi.org/10.3390/en16093968 - 08 May 2023
Cited by 1 | Viewed by 2218
Abstract
Unmanned aerial vehicles (UAV)s have unique requirements that demand engines with high power-to-weight ratios, fuel efficiency, and reliability. As such, combustion engines used in UAVs are specialized to meet these requirements. There are several types of combustion engines used in UAVs, including reciprocating [...] Read more.
Unmanned aerial vehicles (UAV)s have unique requirements that demand engines with high power-to-weight ratios, fuel efficiency, and reliability. As such, combustion engines used in UAVs are specialized to meet these requirements. There are several types of combustion engines used in UAVs, including reciprocating engines, turbine engines, and Wankel engines. Recent advancements in engine design, such as the use of ceramic materials and microscale combustion, have the potential to enhance engine performance and durability. This article explores the potential use of combustion-based engines, particularly microjet engines, as an alternative to electrically powered unmanned aerial vehicle (UAV) systems. It provides a review of recent developments in UAV engines and micro combustors, as well as studies on flame stabilization techniques aimed at enhancing engine performance. Heat recirculation methods have been proposed to minimize heat loss to the combustor walls. It has been demonstrated that employing both bluff-body stabilization and heat recirculation methods in narrow channels can significantly improve combustion efficiency. The combination of flame stabilization and heat recirculation methods has been observed to significantly improve the performance of micro and mesoscale combustors. As a result, these technologies hold great promise for enhancing the performance of UAV engines. Full article
(This article belongs to the Section I: Energy Fundamentals and Conversion)
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18 pages, 17292 KiB  
Article
Grid-Connected Phase-Locked Loop Technology Based on a Cascade Second-Order IIR Filter
by Shanwen Ke and Yuren Li
Energies 2023, 16(9), 3967; https://doi.org/10.3390/en16093967 - 08 May 2023
Cited by 2 | Viewed by 1085
Abstract
The moving average filter-based phase-locked loop (MAF-PLL) can obtain grid synchronization signals accurately under adverse grid conditions with a large amount of harmonics due to the high filtering capability of the MAF. However, MAF-PLL cannot achieve a fast dynamic response in the case [...] Read more.
The moving average filter-based phase-locked loop (MAF-PLL) can obtain grid synchronization signals accurately under adverse grid conditions with a large amount of harmonics due to the high filtering capability of the MAF. However, MAF-PLL cannot achieve a fast dynamic response in the case of frequency drift, phase angle steps, and unbalanced voltage sag. MAF is essentially an FIR filter, and its filtering performance is hard to be adjusted. To address this issue, this paper proposes an alternative to MAF consisting of a set of cascading second-order IIR filters (CIIRF). Based on MAF, CIIRF introduces multiple zeros and poles from the zero–pole replacement perspective, and by changing the position of the poles, the filter performance can be adjusted. To improve the anti-interference ability of PLL based on CIIRF (CIIRF-PLL) in the presence of grid frequency drift, a frequency-adaptive scheme is also proposed. Simulation and experimental results show that CIIRF-PLL can accurately track the grid voltage phase in the case of frequency steps, phase angle jumps, harmonics injection, and unbalanced voltage sag and has good steady-state and dynamic performance. Full article
(This article belongs to the Special Issue Control of Renewable Power Generation and Microgrids)
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17 pages, 4683 KiB  
Article
Combined Utilization of Cylinder and Different Shaped Alumina Nanoparticles in the Base Fluid for the Effective Cooling System Design of Lithium-Ion Battery Packs
by Fatih Selimefendigil, Furkan Dilbaz and Hakan F. Öztop
Energies 2023, 16(9), 3966; https://doi.org/10.3390/en16093966 - 08 May 2023
Cited by 3 | Viewed by 1417
Abstract
It is important to consider the thermal management of lithium-ion batteries to overcome their limitations in usage and improve their performance and life cycles. In this study, a novel cooling system for the thermal management of lithium-ion battery packs is proposed by using [...] Read more.
It is important to consider the thermal management of lithium-ion batteries to overcome their limitations in usage and improve their performance and life cycles. In this study, a novel cooling system for the thermal management of lithium-ion battery packs is proposed by using an inner cylinder in the cooling channel and different-shaped nanoparticles in the base fluid, which is used as the cooling medium. The performance improvements in a 20 Ah capacity battery are compared by using a water–boehmite alumina (AlOOH) nanofluid, considering cylinder-, brick-, and blade-shaped nanoparticles up to a solid volume fraction of 2%. The numerical analysis is conducted using the finite element method, and Reynolds numbers between 100 and 600 are considered. When the efficacy of the coolants utilized is compared, it is apparent that as the Reynolds number increases, both cooling media decrease the highest temperature and homogenize the temperatures in the battery. The utilization of the cylinder in the mini-channel results in a 2 °C temperature drop at Re = 600 as compared to the flat channel. A boehmite alumina nanofluid with a 2% volume fraction reduces the maximum temperature by 5.1% at Re = 200. When the shape effect of the nanofluid is examined, it is noted that the cylinder-shaped particle improves the temperature by 4.93% as compared to blade-shaped nanoparticles and 7.32% as compared to brick-shaped nanoparticles. Thus, the combined utilization of a nanofluid containing cylindrical-shaped nanoparticles as the cooling medium and a cylinder in the mini-channel of a battery thermal management system provides an effective cooling system for the thermal management of the battery pack. The outcomes of this work are helpful for further system design and optimization studies related to battery thermal management. Full article
(This article belongs to the Section D3: Nanoenergy)
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39 pages, 9131 KiB  
Article
Novel Harmonic Distortion Prediction Methods for Meshed Transmission Grids with Large Amount of Underground Cables
by Vladislav Akhmatov, Bjarne Søndergaard Bukh, Chris Liberty Skovgaard and Bjarne Christian Gellert
Energies 2023, 16(9), 3965; https://doi.org/10.3390/en16093965 - 08 May 2023
Cited by 2 | Viewed by 1220
Abstract
The tremendous and fast green transition in Denmark has initiated the large-scale grid-integration of renewable energy sources, electrification of energy consumption, and establishment of PtX and Energy Islands, setting goals for transmission grid development—such as the establishment of new connections—and for grid reconstruction—such [...] Read more.
The tremendous and fast green transition in Denmark has initiated the large-scale grid-integration of renewable energy sources, electrification of energy consumption, and establishment of PtX and Energy Islands, setting goals for transmission grid development—such as the establishment of new connections—and for grid reconstruction—such as the extensive substitution of overhead lines (OHLs) with underground cables (UGCs). The share of UGCs in the Danish transmission grid is increasing. Presence of UGC has resulted in that resonances of the harmonic impedance characteristics of the transmission grid are brought within the harmonic order range coinciding with the harmonic emission sources and causing systemwide increase of the harmonic voltage distortion in the 400 kV transmission grid. The transformation of the 400 kV transmission grid has given rise to the need to predict harmonic voltage distortion using simulation models to secure an adequate power quality and support investment decisions and harmonic mitigation for the grid stage, which has not yet been established and which differs from the present grid. This paper presents the experiences of Energinet, the Transmission System Operator (TSO) in Denmark, with harmonic distortion in the Danish transmission grid due to the establishment of 400 kV UGCs, and the development of measurement-validated methods for harmonic distortion simulation and prediction. The paper also presents ongoing developments within, and research addressing, the prediction of harmonic distortion in meshed grids; for example, it explores where and how an analytical approach can replace observational studies with many numerical simulations. The methods shall make it possible to predict whether, where in the transmission grid, and for which harmonic orders connections that have not yet been commissioned may cause the violation of the planning levels, and which mitigations are necessary for bringing the harmonic distortion below the planning levels with respect to a given margin. Full article
(This article belongs to the Topic Power Quality)
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19 pages, 2640 KiB  
Article
Adaptive Control Strategy for Stationary Electric Battery Storage Systems with Reliable Peak Load Limitation at Maximum Self-Consumption of Locally Generated Energy
by Florian Klausmann and Anna-Lena Klingler
Energies 2023, 16(9), 3964; https://doi.org/10.3390/en16093964 - 08 May 2023
Viewed by 1217
Abstract
Nowadays, stationary battery storage systems are generally used to optimize the self-consumption of electricity generated locally or to limit the peak load of the local grid connection. Self-consumption optimization aims to achieve economic benefits by using more of the self-generated electricity within the [...] Read more.
Nowadays, stationary battery storage systems are generally used to optimize the self-consumption of electricity generated locally or to limit the peak load of the local grid connection. Self-consumption optimization aims to achieve economic benefits by using more of the self-generated electricity within the local grid. Batteries used for the optimization of self-consumption tend to present low states of charge and, therefore, normally do not contribute to peak load limitation. Peak load limitation is used to minimize the grid connection power to enable more cost-efficient grid connections. However, this function can only be achieved year-round if there is sufficient surplus electricity production or if the battery can be charged from the grid. In the latter case, the batteries are often fully charged and do not significantly optimize the self-consumption. This study presents a new operating strategy that combines all the advantages of the previous operating modes with none of the disadvantages. This can be accomplished by combining the operation modes depending on the particular situation, together with a variable battery charging process. Furthermore, a simulation-based optimization procedure is introduced for the optimal configuration of the parameters. The potential of this operating strategy is demonstrated based on application examples. As a result, the operating strategy enables reliable peak load limitation all year round while simultaneously optimizing self-consumption. The operating strategy can easily be adapted to meet changing requirements such as the increasing charging power demands of electric vehicles. Thanks to a simple process based on common measured variables, the operating strategy can be integrated smoothly into practical applications. Full article
(This article belongs to the Special Issue Optimal Planning, Integration and Control of Smart Microgrid Systems with Renewable Energy)
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18 pages, 5976 KiB  
Article
Risk Assessment of a Hydrogen Refueling Station in an Urban Area
by Jongbeom Kwak, Haktae Lee, Somin Park, Jaehyuk Park and Seungho Jung
Energies 2023, 16(9), 3963; https://doi.org/10.3390/en16093963 - 08 May 2023
Cited by 4 | Viewed by 2041
Abstract
After the Paris Agreement was signed in 2015, many countries worldwide focused on the hydrogen economy, aiming for eco-friendly and renewable energy by moving away from the existing carbon economy, which has been the primary source of global warming. Hydrogen is the most [...] Read more.
After the Paris Agreement was signed in 2015, many countries worldwide focused on the hydrogen economy, aiming for eco-friendly and renewable energy by moving away from the existing carbon economy, which has been the primary source of global warming. Hydrogen is the most common element on Earth. As a light substance, hydrogen can diffuse quickly; however, it also has a small risk of explosion. Representative explosion accidents have included the Muskingum River Power Plant Vapor Cloud Explosion accident in 2007 and the Silver Eagle Refinery Vapor Cloud Explosion accident in 2009. In addition, there was an explosion in a hydrogen tank in Gangneung, Korea, in May 2019, and a hydrogen refueling station (HRS) in Norway exploded in 2018. Despite this risk, Korea is promoting the establishment of HRSs in major urban centers, including downtown areas and public buildings, by using the Regulatory Sandbox to install HRSs. This paper employed the Hydrogen Risk Assessment Model (HyRAM) of Sandia National Laboratories (SNL), a quantitative risk assessment (QRA) program specialized in hydrogen energy for HRSs installed in major urban hubs. A feasibility evaluation of the site conditions of an HRS was conducted using the French land use planning method based on the results obtained through evaluation using the HyRAM and the overpressure results of PHAST 8.0. After a risk assessment, we confirmed that an HRS would be considered safe, even if it was installed in the city center within a radius of influence of jet fires and overpressure. Full article
(This article belongs to the Special Issue Latest Advances and Prospects of Hydrogen Safety)
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29 pages, 12577 KiB  
Review
The Fuel Flexibility of Gas Turbines: A Review and Retrospective Outlook
by Michel Molière
Energies 2023, 16(9), 3962; https://doi.org/10.3390/en16093962 - 08 May 2023
Cited by 3 | Viewed by 4392
Abstract
Land-based gas turbines (GTs) are continuous-flow engines that run with permanent flames once started and at stationary pressure, temperature, and flows at stabilized load. Combustors operate without any moving parts and their substantial air excess enables complete combustion. These features provide significant space [...] Read more.
Land-based gas turbines (GTs) are continuous-flow engines that run with permanent flames once started and at stationary pressure, temperature, and flows at stabilized load. Combustors operate without any moving parts and their substantial air excess enables complete combustion. These features provide significant space for designing efficient and versatile combustion systems. In particular, as heavy-duty gas turbines have moderate compression ratios and ample stall margins, they can burn not only high- and medium-BTU fuels but also low-BTU ones. As a result, these machines have gained remarkable fuel flexibility. Dry Low Emissions combustors, which were initially confined to burning standard natural gas, have been gradually adapted to an increasing number of alternative gaseous fuels. The paper first delivers essential technical considerations that underlie this important fuel portfolio. It then reviews the spectrum of alternative GT fuels which currently extends from lean gases (coal bed, coke oven, blast furnace gases…) to rich refinery streams (LPG, olefins) and from volatile liquids (naphtha) to heavy hydrocarbons. This “fuel diet” also includes biogenic products (biogas, biodiesel, and ethanol) and especially blended and pure hydrogen, the fuel of the future. The paper also outlines how, historically, land-based GTs have gradually gained new fuel territories thanks to continuous engineering work, lab testing, experience extrapolation, and validation on the field. Full article
(This article belongs to the Topic Evolution of Land-Based Gas Turbines)
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20 pages, 538 KiB  
Article
Consumer Preferences for Smart Energy Services Based on AMI Data in the Power Sector
by Hye-Jeong Lee, Beom Jin Chung and Sung-Yoon Huh
Energies 2023, 16(9), 3961; https://doi.org/10.3390/en16093961 - 08 May 2023
Cited by 1 | Viewed by 1371
Abstract
Advanced metering infrastructure (AMI) is becoming increasingly popular as an efficient means of energy demand management. By collecting energy data through AMI, it is possible to provide users with information that can induce them to change their behavior. To ensure that AMI continues [...] Read more.
Advanced metering infrastructure (AMI) is becoming increasingly popular as an efficient means of energy demand management. By collecting energy data through AMI, it is possible to provide users with information that can induce them to change their behavior. To ensure that AMI continues to expand and to encourage the use of energy data, it is important to increase consumer participation and analyze their preferred service attributes. This study utilized a choice experiment to analyze consumer preferences for and acceptance of smart energy services based on AMI data. The results of a mixed logit model estimation show that consumers prefer the electricity information service for individual households and the social safety-net service among convergence services. A scenario analysis confirms that monetary compensation to offset any additional charges is important to maintain the level of consumer acceptance. These empirical findings offer insights for policymakers and companies seeking to develop policies and similar services. Full article
(This article belongs to the Special Issue Policies for Carbon-Neutral Energy System)
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23 pages, 4023 KiB  
Article
An MV-Connected Ultra-Fast Charging Station Based on MMC and Dual Active Bridge with Multiple dc Buses
by Marzio Barresi, Edoardo Ferri and Luigi Piegari
Energies 2023, 16(9), 3960; https://doi.org/10.3390/en16093960 - 08 May 2023
Cited by 2 | Viewed by 1688
Abstract
The diffusion of electric vehicles will be strongly related to the capacity to charge them in short times. To do so, the necessity of widespread fast charging stations arises. However, their intermittent demand represents a challenging load for grid operators. In order to [...] Read more.
The diffusion of electric vehicles will be strongly related to the capacity to charge them in short times. To do so, the necessity of widespread fast charging stations arises. However, their intermittent demand represents a challenging load for grid operators. In order to relieve their impact on the electrical grid operation, integrating storage systems in the charging stations represents a potential solution, although it complicates the overall system management. Moreover, standard converter architectures for the MV grid interface require the installation of bulky transformers and filters. In order to cope with the mentioned problems, this paper proposes an ultra-fast charging station topology based on a modular multilevel converter (MMC) structure and dual-active bridge (DAB) converters. Thanks to the multilevel converter properties, the proposed charging station can be directly interfaced with the MV grid without requiring transformers or filters. Additionally, exploiting the degree of freedom in the converter control system, such as circulating components, offers uneven power distribution among the converter submodules that can be managed. Along with the MMC control strategy, the article addresses a straightforward methodology to select the main parameters of the DAB converter as a function of the involved grid power and circulating power contributions, with the primary goal of obtaining a trade-off between internal balancing performances and a broad soft-switching region without incurring in converter oversizing. The effectiveness of the proposed charging station is finally discussed through numerical simulations, where its behavior during a power demand cycle is analyzed. Full article
(This article belongs to the Collection Editorial Board Members’ Collection Series: Advances in Power Converters)
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59 pages, 1515 KiB  
Review
Renewable Energy Potential and CO2 Performance of Main Biomasses Used in Brazil
by Elem Patricia Rocha Alves, Orlando Salcedo-Puerto, Jesús Nuncira, Samuel Emebu and Clara Mendoza-Martinez
Energies 2023, 16(9), 3959; https://doi.org/10.3390/en16093959 - 08 May 2023
Cited by 1 | Viewed by 2503
Abstract
This review investigates the effects of the Brazilian agriculture production and forestry sector on carbon dioxide (CO2) emissions. Residual biomasses produced mainly in the agro-industrial and forestry sector as well as fast-growing plants were studied. Possibilities to minimize source-related emissions by [...] Read more.
This review investigates the effects of the Brazilian agriculture production and forestry sector on carbon dioxide (CO2) emissions. Residual biomasses produced mainly in the agro-industrial and forestry sector as well as fast-growing plants were studied. Possibilities to minimize source-related emissions by sequestering part of carbon in soil and by producing biomass as a substitute for fossil fuel were extensively investigated. The lack of consistency among literature reports on residual biomass makes it difficult to compare CO2 emission reductions between studies and sectors. Data on chemical composition, heating value, proximate and ultimate analysis of the biomasses were collected. Then, the carbon sequestration potential of the biomasses as well as their usability in renewable energy practices were studied. Over 779.6 million tons of agricultural residues were generated in Brazil between 2021 and 2022. This implies a 12.1 million PJ energy potential, while 4.95 million tons of forestry residues was generated in 2019. An estimated carbon content of 276 Tg from these residues could lead to the production of approximately 1014.2 Tg of CO2. Brazilian biomasses, with a particular focus on agro-forest waste, can contribute to the development of sustainable alternative energy sources. Moreover, agro-waste can provide carbon credits for sustainable Brazilian agricultural development. Full article
(This article belongs to the Section A4: Bio-Energy)
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23 pages, 8600 KiB  
Article
Analysis and Design of a New High Voltage Gain Interleaved DC–DC Converter with Three-Winding Coupled Inductors for Renewable Energy Systems
by Shin-Ju Chen, Sung-Pei Yang, Chao-Ming Huang and Ping-Sheng Huang
Energies 2023, 16(9), 3958; https://doi.org/10.3390/en16093958 - 08 May 2023
Cited by 2 | Viewed by 1357
Abstract
In this article, a new non-isolated interleaved DC–DC converter is proposed to provide a high voltage conversion ratio in renewable energy systems. The converter configuration is composed of a two-phase interleaved boost converter integrating a voltage-lift capacitor and three-winding coupled inductor-based voltage multiplier [...] Read more.
In this article, a new non-isolated interleaved DC–DC converter is proposed to provide a high voltage conversion ratio in renewable energy systems. The converter configuration is composed of a two-phase interleaved boost converter integrating a voltage-lift capacitor and three-winding coupled inductor-based voltage multiplier modules to achieve high step-up voltage conversion and reduce voltage stresses on the semiconductors (switches and diodes). The converter can achieve a high voltage conversion ratio when working at a proper duty ratio. The voltage stresses on the switches are significantly lower than the output voltage, which enables engineers to adopt low-voltage-rating MOSFETs with low on-state resistance. The switches can turn on under zero-current switching (ZCS) conditions because of the leakage inductor series reducing switching losses. Some diodes can naturally turn off under ZCS conditions to alleviate the reverse–recovery issue and to reduce reverse–recovery losses. The input current has small ripples due to the interleaved operation. The leakage inductor energy is recycled and voltage spikes on the switches are avoided. The proposed converter is suitable for applications in which high voltage gain, high efficiency and high power are required. The principle of operation, steady-state analysis and design considerations of the proposed converter are described in detail. In addition, a closed-loop controller is designed to reduce the effect of input voltage fluctuation and load change on the output voltage. Finally, a 1000 W laboratory prototype is built and tested. The theoretical analysis and the performance of the proposed converter were validated by the experimental results. Full article
(This article belongs to the Special Issue Advanced Application of Power Electronics in Power Systems)
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31 pages, 13763 KiB  
Review
Innovative Approaches to Solar Desalination: A Comprehensive Review of Recent Research
by Ahmed E. Abu El-Maaty, Mohamed M. Awad, Gamal I. Sultan and Ahmed M. Hamed
Energies 2023, 16(9), 3957; https://doi.org/10.3390/en16093957 - 08 May 2023
Cited by 6 | Viewed by 2170
Abstract
Solar desalination systems are a promising solution to the water scarcity problem since the majority of the earth’s water resources are salty. With the increasing focus on desalination research, many innovative methods are being developed to extract salts from saline water. Energy consumption [...] Read more.
Solar desalination systems are a promising solution to the water scarcity problem since the majority of the earth’s water resources are salty. With the increasing focus on desalination research, many innovative methods are being developed to extract salts from saline water. Energy consumption is a significant concern in desalination, and renewable energy, particularly solar energy, is considered a viable alternative to fossil fuel energy. In this review, we will focus on direct and indirect solar desalination methods, specifically traditional direct solar desalination methods such as solar still and humidification dehumidification (HDH) desalination systems. We will also briefly discuss a recent advancement in the desalination method known as the fogging process, which is a development of the HDH desalination system. Full article
(This article belongs to the Special Issue Applied Solar Thermal Energy)
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29 pages, 5529 KiB  
Review
State-of-the-Art Grid Stability Improvement Techniques for Electric Vehicle Fast-Charging Stations for Future Outlooks
by Kabir Momoh, Shamsul Aizam Zulkifli, Petr Korba, Felix Rafael Segundo Sevilla, Arif Nur Afandi and Alfredo Velazquez-Ibañez
Energies 2023, 16(9), 3956; https://doi.org/10.3390/en16093956 - 08 May 2023
Cited by 3 | Viewed by 2231
Abstract
The growing trend for electric vehicles (EVs) and fast-charging stations (FCSs) will cause the overloading of grids due to the high current injection from FCSs’ converters. The insensitive nature of the state of charge (SOC) of EV batteries during FCS operation often results [...] Read more.
The growing trend for electric vehicles (EVs) and fast-charging stations (FCSs) will cause the overloading of grids due to the high current injection from FCSs’ converters. The insensitive nature of the state of charge (SOC) of EV batteries during FCS operation often results in grid instability problems, such as voltage and frequency deviation at the point of common coupling (PCC). Therefore, many researchers have focused on two-stage converter control (TSCC) and single-stage converter (SSC) control for FCS stability enhancement, and suggested that SSC architectures are superior in performance, unlike the TSCC methods. However, only a few research works have focused on SSC techniques, despite the techniques’ ability to provide inertia and damping support through the virtual synchronous machine (VSM) strategy due to power decoupling and dynamic response problems. TSCC methods deploy current or voltage control for controlling EVs’ SOC battery charging through proportional-integral (PI), proportional-resonant (PR), deadbeat or proportional-integral-derivative (PID) controllers, but these are relegated by high current harmonics, frequency fluctuation and switching losses due to transient switching. This paper reviewed the linkage between the latest research contributions, issues associated with TSCC and SSC techniques, and the performance evaluation of the techniques, and subsequently identified the research gaps and proposed SSC control with SOC consideration for further research studies. Full article
(This article belongs to the Special Issue Advanced Operation, Control, and Optimization of Grid-Integrated Renewable Energy Systems)
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16 pages, 5425 KiB  
Article
Economic Dispatch Optimization of a Microgrid with Wind–Photovoltaic-Load-Storage in Multiple Scenarios
by Haipeng Wang, Xuewei Wu, Kai Sun, Xiaodong Du, Yuling He and Kaiwen Li
Energies 2023, 16(9), 3955; https://doi.org/10.3390/en16093955 - 08 May 2023
Cited by 2 | Viewed by 1103
Abstract
The optimal economic power dispatching of a microgrid is an important part of the new power system optimization, which is of great significance to reduce energy consumption and environmental pollution. The microgrid should not only meet the basic demand of power supply but [...] Read more.
The optimal economic power dispatching of a microgrid is an important part of the new power system optimization, which is of great significance to reduce energy consumption and environmental pollution. The microgrid should not only meet the basic demand of power supply but also improve the economic benefit. Considering the generation cost, the discharge cost, the power purchase cost, the electricity sales revenue, the battery charging and discharging power constraints, and the charging and discharging time constraints, a joint optimization model for a multi-scenario microgrid with wind–photovoltaic-load storage is proposed in our study. Additionally, the corresponding model solving algorithm based on particle swarm optimization is also given. In addition, taking the Wangjiazhai project in Baiyangdian region as a case study, the effectiveness of the proposed model and algorithm is verified. The joint optimization model for a microgrid with wind–photovoltaic-load storage in multiple scenarios is discussed and investigated, and the optimal economic power dispatching schemes in multiple scenarios are also provided. Our research shows that: (1) the battery can play a role in peak shaving and valley filling, which can make microgrids more economical; (2) when the power purchase price is lower than the cost of renewable energy power generation, if the wind turbine and the photovoltaics are allowed to be discarded the microgrid will produce higher economic benefits; and (3) restricting the exchange power between the microgrid and the main power network will lead to a negative impact on the economy for the microgrid. Full article
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17 pages, 9895 KiB  
Article
The Effect of an Electric Field on the Sliding Friction of the Silicone Rubber against Selected Metals in Motor Base Oils
by Marek Głogowski, Daniel Smykowski and Sławomir Pietrowicz
Energies 2023, 16(9), 3954; https://doi.org/10.3390/en16093954 - 08 May 2023
Viewed by 1052
Abstract
The effects of applying external electric fields on the coefficient of friction of a selected elastomer during mechanical interaction with steel and copper surface oil (counter samples) immersed in a pin-on-disc setup were studied and investigated. The synthetic base oils used were PAG [...] Read more.
The effects of applying external electric fields on the coefficient of friction of a selected elastomer during mechanical interaction with steel and copper surface oil (counter samples) immersed in a pin-on-disc setup were studied and investigated. The synthetic base oils used were PAG 68 and PAO 6. The elastomer selected for the study is commonly used in the manufacture of rotary lip seals. During the investigations, the viscosity of the oils tested was also experimentally determined in the temperature range of between 286 K and 393 K. It was found that the external electric field had a significant effect on the friction coefficient, depending on the type of base oil, the angular velocity of the load force, and the counterpart. It was observed that for both oils tested, the coefficient of friction values decreased by about 30% when an external DC electric field was applied. In addition, a simple numerical model of the friction interface was proposed and studied. The experimental results were complemented by molecular simulations to determine the interaction between the lubricant molecule and the metal surface. Furthermore, molecular models of the metal surface and lubricant molecules were simulated using ReaxFF and COMPASS force fields to determine adsorption energies. Full article
(This article belongs to the Section F: Electrical Engineering)
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21 pages, 3975 KiB  
Article
Power Distribution System Outage Management Using Improved Resilience Metrics for Smart Grid Applications
by Arif Fikri Malek, Hazlie Mokhlis, Nurulafiqah Nadzirah Mansor, Jasrul Jamani Jamian, Li Wang and Munir Azam Muhammad
Energies 2023, 16(9), 3953; https://doi.org/10.3390/en16093953 - 08 May 2023
Cited by 4 | Viewed by 1286
Abstract
Smart grid systems play a significant role in improving the resilience of distribution systems (DSs). In this paper, two strategies are proposed for implementation of a smart grid application: (a) a network reconfiguration and (b) a network reconfiguration with mobile emergency generator (MEGs) [...] Read more.
Smart grid systems play a significant role in improving the resilience of distribution systems (DSs). In this paper, two strategies are proposed for implementation of a smart grid application: (a) a network reconfiguration and (b) a network reconfiguration with mobile emergency generator (MEGs) deployment. An improved set of resilience metrics to quantify and enhance the resiliency of distribution systems (DSs) is developed for the proposed optimization. The metrics aim to determine a suitable strategy and the optimal number and capacity of MEGs to restore the disconnected loads through the development of several microgrids. These metrics are then aggregated with the proposed strategy to develop an automated solution provider. The objective is to maximize system resilience considering the priority loads. The proposed resilience metrics are tested on the IEEE 33-Bus radial DSs. The case studies conducted proved the performance of the proposed power outage management strategy and resilience metrics in maximizing system resiliency for smart grids. Full article
(This article belongs to the Special Issue Advances in Smart Grid Power Systems: Uncertainty, Resilience, and Interdependence)
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19 pages, 7356 KiB  
Article
Model-Based Performance Optimization of Thermal Management System of Proton Exchange Membrane Fuel Cell
by Jiaming Zhang, Fuwu Yan, Changqing Du, Wenhao Li, Hongzhang Fang and Jun Shen
Energies 2023, 16(9), 3952; https://doi.org/10.3390/en16093952 - 08 May 2023
Viewed by 1180
Abstract
As a promising new power source, the proton exchange membrane fuel cell (PEMFC) has attracted extensive attention. The PEMFC engine produces a large amount of waste heat during operation. The excessive temperature will reduce the efficiency and lifespan of PEMFC engine and even [...] Read more.
As a promising new power source, the proton exchange membrane fuel cell (PEMFC) has attracted extensive attention. The PEMFC engine produces a large amount of waste heat during operation. The excessive temperature will reduce the efficiency and lifespan of PEMFC engine and even cause irreversible damage if not taken away in time. The thermal management system of the PEMFC plays a critical role in efficiency optimization, longevity and operational safety. To solve the problem of high heat production in the operation of the PEMFC, two approaches are proposed to improve the heat dissipation performance of the radiators in thermal management systems. Three kinds of nanofluids with excellent electrical and thermal conductivity–Al2O3, SiO2 and ZnO– are employed as the cooling medium. The radiator parameters are optimized to improve the heat transfer capability. A typical 1D thermal management system and an isotropic 3D porous medium model replacing the wavy fin are constructed to reveal the effects of the nanofluid and the parameters of the radiator performance and the thermal management system. The results show that all three kinds of nanofluids can effectively improve the heat transfer capacity of the coolant, among which the comprehensive performance of the Al2O3 nanofluid is best. When the mass flow rate is 0.04 kg/s and the concentration is 0.5 vol%, the amount of heat transfer of the Al2O3 nanofluid increases by 12.7% when compared with pure water. Under the same conditions, it can reduce the frontal area of the radiator by 12%. For the radiator, appropriate reduction of the fin pitch and wavy length and increase of wave amplitude can effectively improve the spread of heat. The use of fin parameters with higher heat dissipation power results in lower coolant temperatures at the inlet and outlet of the stack. The performance of the radiator is predicted by the two model-based approaches described above which provide a reliable theoretical basis for the optimization of the thermal management system and the matching of the components. Full article
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22 pages, 7389 KiB  
Article
Energy Management Strategies of Grid-Connected Microgrids under Different Reliability Conditions
by Mohammed Abdullah H. Alshehri, Youguang Guo and Gang Lei
Energies 2023, 16(9), 3951; https://doi.org/10.3390/en16093951 - 08 May 2023
Viewed by 1157
Abstract
The demand for a reliable, cheap and environmentally friendly source of energy makes the integration of renewable energy into power networks a global challenge. Furthermore, reliability, as one of the core elements of efficient and cost-effective energy management options, is still among the [...] Read more.
The demand for a reliable, cheap and environmentally friendly source of energy makes the integration of renewable energy into power networks a global challenge. Furthermore, reliability, as one of the core elements of efficient and cost-effective energy management options, is still among the dominant factors/techniques that receive more attention for realistic penetrations of renewable energy into the electricity grid. This paper proposes an efficient way of energy management for a grid-connected microgrid. The grid-connected microgrid used in the analysis consists of solar photovoltaic (P.V.) and battery. In this microgrid configuration, oftentimes, the output power might not be equal to the system demand; in this regard, it is expected that the mismatch between these output powers is not zero. However, to reduce the mismatch between demand and supply to be close to zero, this paper proposes strategies of increasing the rated power of solar, battery and grid separately and combining them with a view of finding the cheapest option among these strategies. The results have shown that the cost increment for different options is USD 280.792, 84.48 and 48.204 for storage, P.V. and grid, respectively. These have shown that the storage option is the most expansive option for improving P.V. grid-connected microgrids. This is followed immediately by the P.V. option, which is weather dependent. On the other hand, the grid option is the cheapest option for system reliability improvement. This paper is expected to be useful to both new researchers and experts who are working in energy management with an emphasis on the reliability aspect. Full article
(This article belongs to the Special Issue Power Management for Distributed Generators Integrated System)
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20 pages, 22189 KiB  
Article
Design of an Experimental Approach for Characterization and Performance Analysis of High-Frequency Transformer Core Materials
by Daniel van Niekerk, Brydon Schoombie and Pitshou Bokoro
Energies 2023, 16(9), 3950; https://doi.org/10.3390/en16093950 - 08 May 2023
Cited by 1 | Viewed by 1360
Abstract
High-frequency transformer core materials are used in power converter applications due to high efficiency performance. Their volume and weight can be reduced when higher operating frequencies are used but at the expense of an increase in core material losses. Some studies analyzed transformer [...] Read more.
High-frequency transformer core materials are used in power converter applications due to high efficiency performance. Their volume and weight can be reduced when higher operating frequencies are used but at the expense of an increase in core material losses. Some studies analyzed transformer core material performance by using finite element method (FEM) analysis, while others used an experimental model. This study proposes an experimental approach to compare the high-frequency transformer efficiency performance of different core material types. In this way, newly produced core material performance can be rapidly analyzed by comparing it against a known core material type, thereby resulting in the fast identification of improved core material design. This empirical approach makes use of a standard half-bridge inverter topology to enable an analysis of high-frequency transformer core material efficiency performance. Actual voltage and current measurements are used to determine the efficiency and output power performance throughout a specified constant current load range at different switching frequencies. Initially commercial standard polycrystalline or ferrite E-core materials were used to validate the characterization jig performance measured curve trends. The usefulness of the jig is then demonstrated by comparatively analyzing and then verifying the expected performance difference between polycrystalline and nanocrystalline toroidal core materials. Full article
(This article belongs to the Topic Efficient Manufacturing: Materials, Processes, and Systems)
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10 pages, 278 KiB  
Article
Potential of Pine Needle Biomass for Bioethanol Production
by Aleksandra Wawro, Jakub Jakubowski, Weronika Gieparda, Zenon Pilarek and Agnieszka Łacka
Energies 2023, 16(9), 3949; https://doi.org/10.3390/en16093949 - 08 May 2023
Cited by 1 | Viewed by 1928
Abstract
Currently, fossil fuels are used to produce fuels and electricity, which are finite sources and have a negative impact on the natural environment. An excellent alternative to these fuels is biofuels, such as bioethanol from waste forest biomass. Pine needles are one of [...] Read more.
Currently, fossil fuels are used to produce fuels and electricity, which are finite sources and have a negative impact on the natural environment. An excellent alternative to these fuels is biofuels, such as bioethanol from waste forest biomass. Pine needles are one of the most important available forest biomass materials with s significant impact on local understory vegetation. Forest waste biomass, which is a rich source of lignocellulose, can be used in various ways, such as for the eco-economical production of bioethanol. The aim of this study was to analyze the possibilities of bioethanol production from pine needle biomass obtained from forest land following different soil preparations and logging residue management. The pine needle dry matter yield, chemical components of pine needle biomass (cellulose, hemicellulose, lignin), and the amount of ethanol yield per hectare were evaluated. The highest average yield pine needle equal to 6.17 Mg∙ha−1 was observed. Bioethanol yield per hectare from this biomass was the highest for plowing with the LPZ-75 plow and was 1.08 m3∙ha−1. The discussed results were confirmed by detailed statistical analysis. To sum up, the researched pine needle biomass turned out to be an interesting raw material with the potential for bioethanol production. Full article
(This article belongs to the Special Issue Key Technologies and Challenges of Biomass and Bioenergy System)
14 pages, 1917 KiB  
Article
Techno-Economic Analysis of Thermochemical Conversion of Waste Masks Generated in the EU during COVID-19 Pandemic into Energy Products
by Samy Yousef, Vidas Lekavičius and Nerijus Striūgas
Energies 2023, 16(9), 3948; https://doi.org/10.3390/en16093948 - 08 May 2023
Cited by 9 | Viewed by 1524
Abstract
During the COVID-19 pandemic, more than 24 billion pieces of surgical mask waste (WM) were generated in the EU region, with an acute shortage of their management and recycling. Pyrolysis and gasification are among the most promising treatments that were proposed to dispose [...] Read more.
During the COVID-19 pandemic, more than 24 billion pieces of surgical mask waste (WM) were generated in the EU region, with an acute shortage of their management and recycling. Pyrolysis and gasification are among the most promising treatments that were proposed to dispose of WMs and convert them into pyrolysis oil and hydrogen-rich syngas. This work aimed to investigate the techno-economic analysis (TEA) of both treatments in order to assess the feasibility of scaling up. The TEA was carried out using a discounted cash flow model and its data were collected from practical experiments conducted using a fluidised bed pyrolysis reactor and bubbling fluidised bed gasifier system with a capacity of 0.2 kg/h and 1 kg/h, respectively, then upscaling to one tonne/h. The technological evaluation was made based on the optimal conditions that could produce the maximum amount of pyrolysis oil (42.3%) and hydrogen-rich syngas (89.7%). These treatments were also compared to the incineration of WMs as a commercial solution. The discounted payback, simple payback, net present value (NPV), production cost, and internal rate of return (IRR) were the main indicators used in the economic feasibility analysis. Sensitivity analysis was performed using SimLab software with the help of Monte Carlo simulations. The results showed that the production cost of the main variables was estimated at 45.4 EUR/t (gate fee), 71.7 EUR/MWh (electricity), 30.5 EUR/MWh (heat), 356 EUR/t (oil), 221 EUR/t (gaseous), 237 EUR/t (char), and 257 EUR/t (syngas). Meanwhile, the IRR results showed that gasification (12.51%) and incineration (7.56%) have better economic performance, while pyrolysis can produce less revenue (1.73%). Based on the TEA results, it is highly recommended to use the gasification process to treat WMs, yielding higher revenue. Full article
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14 pages, 4642 KiB  
Article
Evaluation of an Energy Separation Device for the Efficiency Improvement of a Planar Solid Oxide Fuel Cell System with an External Reformer
by Jinwon Yun, Eun-Jung Choi, Sangmin Lee, Younghyeon Kim and Sangseok Yu
Energies 2023, 16(9), 3947; https://doi.org/10.3390/en16093947 - 08 May 2023
Viewed by 987
Abstract
Due to the high operating temperature of solid oxide fuel cells (SOFC), the system efficiency depends on efficient thermal integration and the effective construction of system configuration. In this study, nine configurations of system integration design were investigated to evaluate the possible improvement [...] Read more.
Due to the high operating temperature of solid oxide fuel cells (SOFC), the system efficiency depends on efficient thermal integration and the effective construction of system configuration. In this study, nine configurations of system integration design were investigated to evaluate the possible improvement of system efficiency with energy separation devices. The models were developed under the Matlab/Simulink® platform with Thermolib® module. The reference layout of the simulation included an SOFC stack, a compressor, an external reformer with a burner, a three-way valve, a heat exchanger, and a water pump. From the reference case, eight cases extended layouts for the capability of thermal energy utilization with a catalytic converter, SOFC hybridization, and an energy separation device. Since the energy separation device was beneficial to thermal energy utilization via a boost to the gas temperature, electric efficiency, and combined heat and power (CHP) efficiency was improved with the thermal integration of the energy separation device with a turbo generator. Full article
(This article belongs to the Special Issue Effective and Efficient Management Practices in Energy Sources and Energy Consumption)
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28 pages, 935 KiB  
Review
Review on Modeling and Control Strategies of DC–DC LLC Converters for Bidirectional Electric Vehicle Charger Applications
by Houssein Al Attar, Mohamed Assaad Hamida, Malek Ghanes and Miassa Taleb
Energies 2023, 16(9), 3946; https://doi.org/10.3390/en16093946 - 08 May 2023
Cited by 4 | Viewed by 1820
Abstract
Bidirectional DC–DC converters are frequently chosen for applications requiring high power density such as in bidirectional electric vehicle (EV) chargers. Vehicle to Everything (V2X) technology makes the EV battery an electrical energy source. In this article, the use of a DC–DC LLC converter [...] Read more.
Bidirectional DC–DC converters are frequently chosen for applications requiring high power density such as in bidirectional electric vehicle (EV) chargers. Vehicle to Everything (V2X) technology makes the EV battery an electrical energy source. In this article, the use of a DC–DC LLC converter used in a bidirectional EV charger is reviewed. Different modeling approaches of the DC–DC LLC converter, such as small and large signal modeling, are discussed. Common modulation strategies applied to the DC–DC LLC converter in V2X mode, such as Pulse Frequency Modulation (PFM), Pulse Width Modulation (PWM) and Phase-Shift Modulation (PSM), are presented. The new challenge is to present the main characteristics and limitations of each modulation strategy in order to cover the whole operating zone of the EV charger in V2X mode. Furthermore, different control strategies based on a small or large signal model combined with different modulation strategies are highlighted. Linear and nonlinear controllers applied to the DC–DC LLC converter are discussed. Robust controllers are mainly highlighted regarding their advantage in ensuring the control robustness with respect to unexpected disturbances. A comparative study among modulation strategies as well as different control algorithms is conducted in terms of control performance and converter efficiency in V2X mode. Full article
(This article belongs to the Special Issue Control, Estimation, Management and Fault Diagnosis of Electrical Vehicles Applications)
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10 pages, 1085 KiB  
Perspective
Perspectives of Using Sewage Sludge Char in CO2 Sequestration on Degraded and Brownfield Sites
by Marcin Sajdak, Monika Zajemska, Miloud Ouadi, Walter Mucha, Edyta Misztal, Celina Pieszko and Grzegorz Gałko
Energies 2023, 16(9), 3945; https://doi.org/10.3390/en16093945 - 08 May 2023
Viewed by 1132
Abstract
One of the greatest challenges humankind currently faces is global warming, mainly caused by greenhouse gas emissions. Here we have attempted to show how thermal conversion products, specifically from the pyrolysis of biomass wastes such as sewage sludge, can be used effectively and [...] Read more.
One of the greatest challenges humankind currently faces is global warming, mainly caused by greenhouse gas emissions. Here we have attempted to show how thermal conversion products, specifically from the pyrolysis of biomass wastes such as sewage sludge, can be used effectively and equivalently to sequester CO2 in brownfield and degraded areas. Scenarios were devised that showed the significant potential for CO2 sequestration in the form of biochar from sewage sludge deposited on degraded and brownfield areas. With the current amount of sludge production, such sludge could even be used in its entirety as a raw material in pyrolysis processes, where, in addition to the biochar, the heat necessary for drying the sludge could be generated and high-energy gas and liquid fractions could be obtained, which could be used to produce alternative fuels. It is therefore important to consider both the potential for CO2 sequestration on degraded and brownfield sites and the potential for sludge disposal in Europe as viable options for reducing greenhouse gas emissions and promoting sustainable waste management practices. Full article
(This article belongs to the Section B3: Carbon Emission and Utilization)
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17 pages, 5060 KiB  
Article
Toward Improved Urban Building Energy Modeling Using a Place-Based Approach
by Guglielmina Mutani, Pamela Vocale and Kavan Javanroodi
Energies 2023, 16(9), 3944; https://doi.org/10.3390/en16093944 - 07 May 2023
Cited by 5 | Viewed by 1787
Abstract
Urban building energy models present a valuable tool for promoting energy efficiency in building design and control, as well as for managing urban energy systems. However, the current models often overlook the importance of site-specific characteristics, as well as the spatial attributes and [...] Read more.
Urban building energy models present a valuable tool for promoting energy efficiency in building design and control, as well as for managing urban energy systems. However, the current models often overlook the importance of site-specific characteristics, as well as the spatial attributes and variations within a specific area of a city. This methodological paper moves beyond state-of-the-art urban building energy modeling and urban-scale energy models by incorporating an improved place-based approach to address this research gap. This approach allows for a more in-depth understanding of the interactions behind spatial patterns and an increase in the number and quality of energy-related variables. The paper outlines a detailed description of the steps required to create urban energy models and presents sample application results for each model. The pre-modeling phase is highlighted as a critical step in which the geo-database used to create the models is collected, corrected, and integrated. We also discuss the use of spatial auto-correlation within the geo-database, which introduces new spatial-temporal relationships that describe the territorial clusters of complex urban environment systems. This study identifies and redefines three primary types of urban energy modeling, including process-driven, data-driven, and hybrid models, in the context of place-based approaches. The challenges associated with each type are highlighted, with emphasis on data requirements and availability concerns. The study concludes that a place-based approach is crucial to achieving energy self-sufficiency in districts or cities in urban-scale building energy-modeling studies. Full article
(This article belongs to the Special Issue Energy Efficient Solutions for Smart and Sustainable Development for the Cities of the Future)
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25 pages, 1785 KiB  
Article
Holistic Approach for an Energy-Flexible Operation of a Machine Tool with Cooling Supply
by Martin Lindner, Benedikt Grosch, Ghada Elserafi, Bastian Dietrich and Matthias Weigold
Energies 2023, 16(9), 3943; https://doi.org/10.3390/en16093943 - 07 May 2023
Cited by 1 | Viewed by 1361
Abstract
The following paper examines the practicality of a methodical approach for energy-flexible and energy-optimal operation in the field of metal-cutting production. The analysis is based on the example of a grinding machine and its central cooling-supply system. In the first step, an energy-flexibility [...] Read more.
The following paper examines the practicality of a methodical approach for energy-flexible and energy-optimal operation in the field of metal-cutting production. The analysis is based on the example of a grinding machine and its central cooling-supply system. In the first step, an energy-flexibility data model is built for each subsystem, which describes energy flexibility potentials generically. This is then extended to enable combined energy cost-optimal production planning. As a basis for the links between the data model representations, the cold flows between the subsystems are modeled using parameter-estimation methods, which have a mean absolute error of only 2.3 percent, making the subsequent installation of heat meters unnecessary. Based on the presented approach, the results successfully validate the possibility of energy-flexible cost-optimal and sensor-reduced production planning by reducing energy costs by 6.6 percent overall and 1.9 percent per workpiece produced. Full article
(This article belongs to the Section D: Energy Storage and Application)
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26 pages, 9217 KiB  
Article
An ECMS Based on Model Prediction Control for Series Hybrid Electric Mine Trucks
by Jichao Liu, Yanyan Liang, Zheng Chen and Hai Yang
Energies 2023, 16(9), 3942; https://doi.org/10.3390/en16093942 - 07 May 2023
Viewed by 1158
Abstract
This paper presents an equivalent consumption minimization strategy (ECMS) based on model predictive control for series hybrid electric mine trucks (SHE-MTs), the objective of which is to minimize fuel consumption. Two critical works are presented to achieve the goal. Firstly, to gain the [...] Read more.
This paper presents an equivalent consumption minimization strategy (ECMS) based on model predictive control for series hybrid electric mine trucks (SHE-MTs), the objective of which is to minimize fuel consumption. Two critical works are presented to achieve the goal. Firstly, to gain the real-time speed trajectory on-line, a speed prediction model is established by utilizing a recurrent neural network (RNN). Specifically, a hybrid optimization algorithm based on the genetic algorithm (GA) and the particle swarm optimization algorithm (PSOA) is used to enhance the prediction precision of the speed prediction model. Then, on this basis, an ECMS based on MPC (ECMS-MPC) is proposed. In this process, to improve the real-time and working condition adaptability of the ECMS-MPC, the power-optimal fuel consumption mapping model of the range extender is established, and the equivalent factor (EF) is real-time adjusted by means of the PSOA. Finally, taking a cement mining road as the research object, the proposed strategy is simulated with the collected actual vehicle data. The experimental results indicate that the prediction precision of the proposed speed prediction model is over 98%, realizing on-line speed prediction effectively. Furthermore, compared to the existing real-time EMSs, its fuel-saving rate had an increase of more than 13%. This indicates that the designed ECMS-MPC is able to offer a novel and effective method for the on-line energy management of the SHE-MTs. Full article
(This article belongs to the Special Issue Energy Management Strategies for Battery and Hybrid Electric Vehicles)
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31 pages, 3374 KiB  
Review
Vehicle Emission Models and Traffic Simulators: A Review
by Maksymilian Mądziel
Energies 2023, 16(9), 3941; https://doi.org/10.3390/en16093941 - 07 May 2023
Cited by 13 | Viewed by 4342
Abstract
Accurate estimations and assessments of vehicle emissions can support decision-making processes. Current emission estimation tools involve several calculation methods that provide estimates of the exhaust components that result from driving on urban arterial roads. This is an important consideration, as the emissions generated [...] Read more.
Accurate estimations and assessments of vehicle emissions can support decision-making processes. Current emission estimation tools involve several calculation methods that provide estimates of the exhaust components that result from driving on urban arterial roads. This is an important consideration, as the emissions generated have a direct impact on the health of pedestrians near the roads. In recent years, there has been an increase in the use of emission models, especially in combination with traffic simulator models. This is because it is very difficult to obtain an actual measurement of road emissions for all vehicles travelling along the analysed road section. This paper concerns a review of selected traffic simulations and the estimation of exhaust gas components models. The models presented have been aggregated into a group with respect to their scale of accuracy as micro, meso, and macro. This paper also presents an overview of selected works that combine both traffic and emission models. The presented literature review also emphasises the proper calibration process of simulation models as the most important factor in obtaining accurate estimates. This work also contains information and recommendations on modelling that may be helpful in selecting appropriate emission estimation tools to support decision-making processes for, e.g., road managers. Full article
(This article belongs to the Special Issue CO2 Emissions from Vehicles (Volume II))
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11 pages, 926 KiB  
Article
Investigating Thermoelectric Batteries Based on Nanostructured Materials
by Svyatoslav Yatsyshyn, Oleksandra Hotra, Pylyp Skoropad, Tetiana Bubela, Mykola Mykyichuk, Orest Kochan and Oksana Boyko
Energies 2023, 16(9), 3940; https://doi.org/10.3390/en16093940 - 07 May 2023
Cited by 1 | Viewed by 1196
Abstract
This article discusses the characteristics of the design of thermoelectric generators (TEGs) for cold climates. Since the thermocouples of thermoelectric batteries are produced from different materials, their major properties are studied. Particular attention is given to nanostructured materials regarding the modern class of [...] Read more.
This article discusses the characteristics of the design of thermoelectric generators (TEGs) for cold climates. Since the thermocouples of thermoelectric batteries are produced from different materials, their major properties are studied. Particular attention is given to nanostructured materials regarding the modern class of thermoelectric materials. Two-, three-, and four-component alloys (metallic glasses) of the Fe-Ni(Cu)-P-B system are chosen based on the experience of thermoelectric thermometry. The close chemical composition of two thermoelectrodes enables their compatibility in thermocouple production and satisfactory thermoelectric efficiency of batteries during long-term operation. The improvement of the thermoelectric battery characteristics related to a unit of mass is evaluated. The materials studied are distinguished by the absence of toxic components harmful to the environment at the manufacturing and operating stages. Full article
(This article belongs to the Special Issue Theory and Applications of Thermoelectric Materials and Devices)
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