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9 pages, 1077 KiB  
Proceeding Paper
Design and Simulation of Ripple Free Non-Inverting DC-DC Cuk Converter with Valley-Fill Circuit for LED Applications
by Lakshmi Praba Balakrishnan, Abhinaya Ravichandran, Seyezhai Ramalingam, Deeikshanyaa Sivasubramaniam and Harini Vasudevan Balamurugan
Eng. Proc. 2025, 93(1), 5; https://doi.org/10.3390/engproc2025093005 - 1 Jul 2025
Viewed by 233
Abstract
LED lighting plays a pivotal role in the illumination landscape owing to its substantial energy efficiency, prolonged operational lifespan, environmental advantages, superior light quality, and its capacity for advanced lighting control. Flicker in led lighting systems has emerged as a substantial concern and [...] Read more.
LED lighting plays a pivotal role in the illumination landscape owing to its substantial energy efficiency, prolonged operational lifespan, environmental advantages, superior light quality, and its capacity for advanced lighting control. Flicker in led lighting systems has emerged as a substantial concern and is appropriate to its potential opposing impacts on human health and visual comfort. Hence, this paper presents a comprehensive analysis, design, and mitigation strategy for flicker in a DC-DC led driver that incorporates a valley fill circuit. The initial stage of this investigation involves an analysis of a conventional cuk converter. However, it is noted that this converter produces an inverting output and experiences high current stress on the semiconductor switch. Consequently, to address these limitations, a non-inverting cuk converter (NICC) is introduced, resulting in a positive output, reduced voltage and current ripple and increased efficiency. To surmount these challenges, the implementation of a valley fill circuit is proposed. This addition facilitates the rapid attainment of a steady state, increases efficiency, and substantially reduces the output voltage and current ripple. An in-depth analysis of the stress imposed on the switch is conducted, leading to the development of a circuit designed to extend the operational life of the LED driver. Therefore, this paper compares the topologies of three different DC-DC cuk power converters. These converters include conventional cuk, non-inverting cuk (NICC), and non-inverting cuk with valley-fill. The performance metrics are examined and compared for all three topologies. The findings of this study affirm that the proposed driver circuit is highly effective in mitigating flicker, thereby enhancing the user experience and elevating the quality of led lighting, all while maintaining energy efficiency. The MATLAB simulations of these converters are performed to validate the theoretical results. Full article
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32 pages, 3036 KiB  
Article
Agricultural Productivity of Solar Pump and Water Harvesting Irrigation Technologies and Their Impacts on Smallholder Farmers’ Income and Food Security: Evidence from Ethiopia
by Mebratu Negera, Zeleke Agide Dejen, Dagmawi Melaku, Desalegn Tegegne, Muluken Elias Adamseged and Amare Haileslassie
Sustainability 2025, 17(4), 1486; https://doi.org/10.3390/su17041486 - 11 Feb 2025
Cited by 1 | Viewed by 3287
Abstract
Irrigation plays a crucial role in enhancing food production, increasing land productivity, and improving the livelihoods of smallholder farmers in Sub-Saharan Africa (SSA). Solar pumps and water harvesting ponds have emerged as promising technologies for sustainable agriculture for smallholders in SSA and beyond. [...] Read more.
Irrigation plays a crucial role in enhancing food production, increasing land productivity, and improving the livelihoods of smallholder farmers in Sub-Saharan Africa (SSA). Solar pumps and water harvesting ponds have emerged as promising technologies for sustainable agriculture for smallholders in SSA and beyond. The socio-economic impacts of these systems are less studied in the existing literature. This study examined the agricultural productivity of solar pump and water harvesting irrigation technologies and their impacts on income and food security among smallholder farmers in the Central Rift Valley, Lake Hawassa, and Upper Awash sub-basin areas in Ethiopia. Data were collected from 161 farming households that were selected randomly from woredas where solar pump and water harvesting pond irrigation systems had been implemented. The sample size was determined using the power calculation method. Bio-physical observation and measurements were also conducted at field levels. The benefit–cost ratio (BCR) and net water value (NWV) from the use of solar pump and water harvesting pond irrigations were analyzed to assess the viability of these systems. The household food consumption score (HFCS) and household dietary diversity score (HDDS) were calculated to measure food security, while the revenue from crop production was used to measure crop income. An endogenous switching regression model was applied to address the endogeneity nature of the adoption of the irrigation technologies. The counterfactual analysis, specifically the Average Treatment Effect on the Treated (ATT), was used to evaluate the impacts of the irrigation technologies on income and food security. Results indicate that the ATT of crop income, HFCS, and HDDS are positive and statistically significant, illustrating the role of these irrigation systems in enhancing smallholder farmers’ welfare. Moreover, smallholder farmers’ solar pump irrigation systems were found to be economically viable for few crops, with a BCR greater than 1.0 and an NWV ranging from 0.21 to 1.53 USD/m³. It was also found that bundling agricultural technologies with solar pump irrigation systems leads to enhanced agricultural outputs and welfare. The sustainable adoption and scale-up of these irrigation systems demand addressing technical and financial constraints, as well as input and output market challenges. Full article
(This article belongs to the Section Economic and Business Aspects of Sustainability)
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22 pages, 826 KiB  
Article
Josephson Junction Dynamics as a Ride on a Roller Coaster
by Ciro Nappi, Carlo Camerlingo and Roberto Cristiano
Physics 2025, 7(1), 2; https://doi.org/10.3390/physics7010002 - 16 Jan 2025
Viewed by 1227
Abstract
We discuss the dynamics of a roller coaster cart driven by a constant force along the suspended track of a winding roller coaster. The track is assumed to be arbitrarily long and specially shaped. It is composed of semicircular track portions, in the [...] Read more.
We discuss the dynamics of a roller coaster cart driven by a constant force along the suspended track of a winding roller coaster. The track is assumed to be arbitrarily long and specially shaped. It is composed of semicircular track portions, in the form of valleys and hills, standing vertically in the same plane. This is a mechanical analog of Josephson junction electrodynamics. To demonstrate the explanatory potential of this analogy, we focus particularly on the conditions of de-trapping of the cart from one of the valleys of the track. This mechanical process has its analog in non-noise-generated premature switching to the finite voltage state of a Josephson junction. Full article
(This article belongs to the Section Physics Education)
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8 pages, 2537 KiB  
Communication
Valley Spin–Polarization of MoS2 Monolayer Induced by Ferromagnetic Order in an Antiferromagnet
by Chun-Wen Chan, Chia-Yun Hsieh, Fang-Mei Chan, Pin-Jia Huang and Chao-Yao Yang
Materials 2024, 17(16), 3933; https://doi.org/10.3390/ma17163933 - 8 Aug 2024
Viewed by 1562
Abstract
Transition metal dichalcogenide (TMD) monolayers exhibit unique valleytronics properties due to the dependency of the coupled valley and spin state at the hexagonal corner of the first Brillouin zone. Precisely controlling valley spin-polarization via manipulating the electron population enables its application in valley-based [...] Read more.
Transition metal dichalcogenide (TMD) monolayers exhibit unique valleytronics properties due to the dependency of the coupled valley and spin state at the hexagonal corner of the first Brillouin zone. Precisely controlling valley spin-polarization via manipulating the electron population enables its application in valley-based memory or quantum technologies. This study uncovered the uncompensated spins of the antiferromagnetic nickel oxide (NiO) serving as the ferromagnetic (FM) order to induce valley spin-polarization in molybdenum disulfide (MoS2) monolayers via the magnetic proximity effect (MPE). Spin-resolved photoluminescence spectroscopy (SR-PL) was employed to observe MoS2, where the spin-polarized trions appear to be responsible for the MPE, leading to a valley magnetism. Results indicate that local FM order from the uncompensated surface of NiO could successfully induce significant valley spin-polarization in MoS2 with the depolarization temperature approximately at 100 K, which is relatively high compared to the related literature. This study reveals new perspectives in that the precise control over the surface orientation of AFMs serves as a crystallographic switch to activate the MPE and the magnetic sustainability of the trion state is responsible for the observed valley spin-polarization with the increasing temperature, which promotes the potential of AFM materials in the field of exchange-coupled Van der Waals heterostructures. Full article
(This article belongs to the Section Materials Physics)
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28 pages, 3104 KiB  
Article
The Economic Feasibility of (Re-)Introducing Tram-Trains in Canada: Okanagan Valley Electric Regional Passenger Rail
by Tye Boray, Mohamed Hegazi, Holger Busche and Gord Lovegrove
Sustainability 2024, 16(10), 4081; https://doi.org/10.3390/su16104081 - 13 May 2024
Viewed by 2231
Abstract
Population and tourism growth has increased congestion, collisions, climate harming emissions, and transport inequities in the Okanagan Valley, British Columbia (B.C.), Canada. Surveys indicate a willingness among residents to switch from cars to public transit featuring better service levels and connections. We conducted [...] Read more.
Population and tourism growth has increased congestion, collisions, climate harming emissions, and transport inequities in the Okanagan Valley, British Columbia (B.C.), Canada. Surveys indicate a willingness among residents to switch from cars to public transit featuring better service levels and connections. We conducted an analysis on the economic feasibility of an Okanagan Valley Electric Regional Passenger Rail (OVER PR) powered by zero-emission (ZE) Fuel Cell/Battery Hybrid Rail (Hydrail) technology along a 342-km route between Osoyoos, B.C., at the US Border and Kamloops, B.C., the Canadian VIA rail hub. Hydrail passenger light-rail has operated successfully since 2018 in Germany and was demonstrated in Quebec, Canada, in 2023. Technical analyses have confirmed the feasibility in B.C. on steep Highway (Hwy) 97 grades and mountainous weather, with mode shift forecasts in the range of 30%. OVER PR economic analyses were also favorable, with net present value (NPV) = CAD 40 billion (CDN, base year 2023), benefit–cost ratio (BCR) = 9:1, and Return on Investments (IRR) = 33% over 30 years. Subject to additional stakeholder consultations and final design reviews, these results were tested against risks using Monte Carlo Simulation (MCS) and Reference-Class Forecasting (RCF), including worst-case risks such as 70% cost over-runs. OVER PR promises an economic transition to clean energy, sustainable transportation, and more livable communities, benefiting all Valley communities through greater transportation equity. Full article
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18 pages, 7097 KiB  
Article
The Quasi-Resonant Structure and Control Strategy of a Photovoltaic Flyback Grid-Connected Microinverter
by Zipei Cao, Annisa binti Jamali, Abdullah Yassin and Ya Huang
Electronics 2024, 13(10), 1903; https://doi.org/10.3390/electronics13101903 - 13 May 2024
Viewed by 1519
Abstract
This study proposes a topology structure for a flyback grid-connected inverter with a compensation capacitor. The addition of the compensation capacitor structure increases the harmonic oscillation period and reduces the switching frequency. Additionally, a control strategy for the microinverter is proposed. By using [...] Read more.
This study proposes a topology structure for a flyback grid-connected inverter with a compensation capacitor. The addition of the compensation capacitor structure increases the harmonic oscillation period and reduces the switching frequency. Additionally, a control strategy for the microinverter is proposed. By using an accurate peak current reference curve, the system ensures precise turn-off signals, thus reducing the harmonic content of the grid-connected current. Simultaneously, the multi-valley turn-on strategy is employed to address the issue of high switching frequency, minimising the impact of energy. The proposed topology structure and control methods are modelled, simulated, and tested to validate the feasibility of the microinverter topology structure and the effectiveness of the control strategy, achieving a maximum efficiency of 95.2% and controlling the total harmonic distortion (THD) below 2.39%. Compared to other microinverter products, it is more efficient and stable. Full article
(This article belongs to the Special Issue Solar Energy Conversions)
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16 pages, 6252 KiB  
Article
Efficiency and PF Improving Techniques with a Digital Control for Totem-Pole Bridgeless CRM Boost PFC Converters
by Jung-Kyu Han
Energies 2024, 17(2), 369; https://doi.org/10.3390/en17020369 - 11 Jan 2024
Cited by 6 | Viewed by 2483
Abstract
A totem-pole bridgeless boost converter is one of the most promising topologies for the power factor correction (PFC) stage in high-power applications due to its high efficiency and small number of components. However, due to the totem-pole structure of the field-effect transistor (FET), [...] Read more.
A totem-pole bridgeless boost converter is one of the most promising topologies for the power factor correction (PFC) stage in high-power applications due to its high efficiency and small number of components. However, due to the totem-pole structure of the field-effect transistor (FET), very high switching loss occurs via the reverse recovery current of the body diode. To solve these problems, critical mode (CRM) control is a good solution to achieve the valley switching technique. With valley switching of CRM control, the switching loss decreases drastically with decreasing turn-on voltage. But, although the CRM control enables valley switching, it is hard to make an exact valley switching control with general zero-voltage detection circuits. In addition, when a frequency limitation scheme is applied to prevent a very high frequency, the switch can operate with hard switching at the boundary of the frequency limitation. Furthermore, the CRM boost PFC has a low PF and high total harmonic distortion (THD) under light-load conditions due to the large negative current resulting from resonance between the inductor and parasitic capacitance. It becomes worse at near-zero input voltage since the resonance current becomes larger near zero-input voltage. Therefore, in this paper, a totem-pole bridgeless boost PFC converter with high efficiency, high PF, and low THD is developed using TMS320F28377 by Texas Instruments. Based on the basic digital structure of the totem-pole bridgeless converter, the proposed controls help with exact valley switching, PF and THD improvement, and frequency limitation. The prototype converter is verified using 90–264 VAC input voltages and 450 V/3.3 kW output specifications. Full article
(This article belongs to the Section F3: Power Electronics)
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17 pages, 3439 KiB  
Article
Two-Layer Cooperative Optimization of Flexible Interconnected Distribution Networks Considering Electric Vehicle User Satisfaction Degree
by Dai Wan, Wenhui Mo, Junhao Li, Chunzhi Yang, Jinbo Wu, Qianfan Zhou and Yusheng Gong
Electronics 2023, 12(22), 4582; https://doi.org/10.3390/electronics12224582 - 9 Nov 2023
Cited by 2 | Viewed by 1500
Abstract
The scaled access of electric vehicles (EVs) exacerbates load fluctuations in distribution networks, which is not conducive to the stable and economic operation of the distribution networks. At present, user satisfaction degree is generally low. To avoid this problem, this paper proposed a [...] Read more.
The scaled access of electric vehicles (EVs) exacerbates load fluctuations in distribution networks, which is not conducive to the stable and economic operation of the distribution networks. At present, user satisfaction degree is generally low. To avoid this problem, this paper proposed a two-layer cooperative optimization of flexible interconnected distribution networks considering EV user satisfaction degree. First, the EV user satisfaction degree model is established by considering EV users’ charging waiting time, charging power, and other indicators. At the same time, an EV charging mode switching model is constructed based on the number of EVs entering the network and their battery charge state. On this basis, the Monte Carlo algorithm is used to generate the results of the daily distribution of EV loads taking into account the user satisfaction degree, so as to improve the load ratio of the transformer in the distribution network. Further, a two-layer cooperative optimization of flexible interconnected distribution networks considering electric vehicle user satisfaction degree is developed with the daily operating cost of each network as the optimization objective. Finally, a flexible interconnected power distribution network consisting of three power distribution networks is used as an example for validation. The results show that this method is effective in improving EV user satisfaction degree and reducing the peak-to-valley ratio of the system load while taking into account the safe and economic operation of the distribution network, which greatly improves the reliability and economy of the operation of the flexible interconnected power distribution network. Full article
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17 pages, 3890 KiB  
Article
A Low Common-Mode SVPWM for Two-Level Three-Phase Voltage Source Inverters
by Jian Zheng, Cunxing Peng, Kaihui Zhao and Mingcheng Lyu
Energies 2023, 16(21), 7294; https://doi.org/10.3390/en16217294 - 27 Oct 2023
Cited by 3 | Viewed by 2855
Abstract
In order to reduce the common-mode voltage (CMV) generated by the use of space vector pulse width modulation (SVPWM) in two-level three-phase voltage source inverters, a low common-mode SVPWM method is proposed. In this method, the voltage plane is divided into 12 sectors, [...] Read more.
In order to reduce the common-mode voltage (CMV) generated by the use of space vector pulse width modulation (SVPWM) in two-level three-phase voltage source inverters, a low common-mode SVPWM method is proposed. In this method, the voltage plane is divided into 12 sectors, and on each sector, two non-zero vectors of the same class and one single zero vector are adopted for synthesis. The action time of the zero vector is placed at both ends of each switching cycle, the currents are sampled at the beginning of each switching cycle, and the action time and sequence of vectors on each sector is provided. Simulation and experimental results show that, in the vector control system of a permanent magnet synchronous motor fed by the inverter, compared with the conventional SVPWM, the proposed method reduces the CMV peak-to-valley value by 33.333%, the CMV jump frequency by three times, and the performance of the line voltage and line current. The electromagnetic torque and rotor speed remain good, which has good application value in high-performance drives. Full article
(This article belongs to the Section F6: High Voltage)
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12 pages, 745 KiB  
Article
Valley-Selective High Harmonic Generation and Polarization Induced by an Orthogonal Two-Color Laser Field
by Xi Liu, Dongdong Liu, Yan Sun, Yujie Li and Cui Zhang
Photonics 2023, 10(10), 1126; https://doi.org/10.3390/photonics10101126 - 8 Oct 2023
Cited by 12 | Viewed by 1771
Abstract
The valley pseudospin properties of electrons in two-dimensional hexagonal materials result in many fascinating physical phenomena, which opens up the new field of valleytronics. The valley-contrasting physics aims at distinguishing the valley degree of freedom based on valley-dependent effects. Here, we theoretically demonstrate [...] Read more.
The valley pseudospin properties of electrons in two-dimensional hexagonal materials result in many fascinating physical phenomena, which opens up the new field of valleytronics. The valley-contrasting physics aims at distinguishing the valley degree of freedom based on valley-dependent effects. Here, we theoretically demonstrate that both of the valley-selective high harmonic generation and valley-selective electronic excitation can be achieved by using an orthogonal two-color (OTC) laser field in gapped graphene. It is shown that the asymmetry degrees of harmonic yields in the plateaus, cutoff energies of generated harmonics and electron populations from two different valleys can be precisely controlled by the relative phase of the OTC laser field. Thus, the selectivity of the dominant valley for the harmonic radiation and electronic polarization can be switched by adjusting the relative phase of the OTC laser field. Our work offers an all-optical route to produce the valley-resolved high harmonic emissions and manipulate the ultrafast valley polarization on a femtosecond timescale in condensed matter. Full article
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13 pages, 6174 KiB  
Article
Development and Implementation of LED Street Lights with Bright and Extinguishable Controls and Power Converters
by Kai-Jun Pai, Liang-Hsun Wang and Ming-Hung Chen
Micromachines 2023, 14(7), 1453; https://doi.org/10.3390/mi14071453 - 20 Jul 2023
Cited by 2 | Viewed by 1684
Abstract
This study developed and implemented a driving power supply for light-emitting diode (LED) array streetlamps. The power stage was a quasi-resonant (QR)-flyback converter, its input power was the alternating-current power, and the LED array streetlamp was driven by the direct-current output power. The [...] Read more.
This study developed and implemented a driving power supply for light-emitting diode (LED) array streetlamps. The power stage was a quasi-resonant (QR)-flyback converter, its input power was the alternating-current power, and the LED array streetlamp was driven by the direct-current output power. The developed QR-flyback converter was operated in discontinuous conduction mode, and the pulse-width modulation (PWM) control chip was used to switch and conduct at the resonant valley of the drain-source voltage on the metal-oxide-semiconductor field-effect transistor (MOSFET) switch to reduce the switching loss. Moreover, the PWM control chip had a disable function, which was connected with a bright and extinguishable control circuit, and the high/low voltage level signal output by the Arduino development board can be used to control the output power of the QR-flyback converter, achieving bright and extinguishable controls for the LED array streetlamp. Full article
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26 pages, 2247 KiB  
Article
A Coaxial Pulsed Plasma Thruster Model with Efficient Flyback Converter Approaches for Small Satellites
by Dillon O’Reilly, Georg Herdrich, Felix Schäfer, Christoph Montag, Simon P. Worden, Peter Meaney and Darren F. Kavanagh
Aerospace 2023, 10(6), 540; https://doi.org/10.3390/aerospace10060540 - 5 Jun 2023
Cited by 4 | Viewed by 3908
Abstract
Pulsed plasma thrusters (PPT) have demonstrated enormous potential since the 1960s. One major shortcoming is their low thrust efficiency, typically <30%. Most of these losses are due to joule heating, while some can be attributed to poor efficiency of the power processing units [...] Read more.
Pulsed plasma thrusters (PPT) have demonstrated enormous potential since the 1960s. One major shortcoming is their low thrust efficiency, typically <30%. Most of these losses are due to joule heating, while some can be attributed to poor efficiency of the power processing units (PPUs). We model PPTs to improve their efficiency, by exploring the use of power electronic topologies to enhance the power conversion efficiency from the DC source to the thruster head. Different control approaches are considered, starting off with the basic approach of a fixed frequency flyback converter. Then, the more advanced critical conduction mode (CrCM) flyback, as well as other optimized solutions using commercial off-the-shelf (COTS) components, are presented. Variations of these flyback converters are studied under different control regimes, such as zero voltage switching (ZVS), valley voltage switching (VVS), and hard switched, to enhance the performance and efficiency of the PPU. We compare the max voltage, charge time, and the overall power conversion efficiency for different operating regimes. Our analytical results show that a more dynamic control regime can result in fewer losses and enhanced performance, offering an improved power conversion efficiency for PPUs used with PPTs. An efficiency of 86% was achieved using the variable frequency approach. This work has narrowed the possible PPU options through analytical analysis and has therefore identified a strategic approach for future investigations. In addition, a new low-power coaxial micro-thruster model using equivalent circuit model elements is developed.This is referred to as the Carlow–Stuttgart model and has been validated against experimental data from vacuum chamber tests in Stuttgart’s Pulsed Plasma Laboratory. This work serves as a valuable precursor towards the implementation of highly optimized PPU designs for efficient PPT thrusters for the next PETRUS (pulsed electrothermal thruster for the University of Stuttgart) missions. Full article
(This article belongs to the Special Issue Numerical Simulations in Electric Propulsion)
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10 pages, 2306 KiB  
Communication
Improving the Output Efficiency of Triboelectric Nanogenerator by a Power Regulation Circuit
by Wenbo Li, Baichuan Leng, Shengyu Hu and Xiaojun Cheng
Sensors 2023, 23(10), 4912; https://doi.org/10.3390/s23104912 - 19 May 2023
Cited by 7 | Viewed by 3832
Abstract
Triboelectric nanogenerator (TENG) is a promising technology for harvesting energy from various sources, such as human motion, wind and vibration. At the same time, a matching backend management circuit is essential to improve the energy utilization efficiency of TENG. Therefore, this work proposes [...] Read more.
Triboelectric nanogenerator (TENG) is a promising technology for harvesting energy from various sources, such as human motion, wind and vibration. At the same time, a matching backend management circuit is essential to improve the energy utilization efficiency of TENG. Therefore, this work proposes a power regulation circuit (PRC) suitable for TENG, which is composed of a valley-filling circuit and a switching step-down circuit. The experimental results indicate that after incorporating a PRC, the conduction time of each cycle of the rectifier circuit doubles, increasing the number of current pulses in the TENG output and resulting in an output charge that is 1.6 fold that of the original circuit. Compared with the initial output signal, the charging rate of the output capacitor increased significantly by 75% with a PRC at a rotational speed of 120 rpm, significantly improving the utilization efficiency of the TENG’s output energy. At the same time, when the TENG powers LEDs, the flickering frequency of LEDs is reduced after adding a PRC, and the light emission is more stable, which further verifies the test results. The PRC proposed in this study can enable the energy harvested by the TENG to be utilized more efficiently, which has a certain promoting effect on the development and application of TENG technology. Full article
(This article belongs to the Topic Advanced Energy Harvesting Technology)
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17 pages, 1512 KiB  
Article
Land Use Misclassification Results in Water Use, Economic Value, and GHG Emission Discrepancies in California’s High-Intensity Agriculture Region
by Vicky Espinoza, Lorenzo Ade Booth and Joshua H. Viers
Sustainability 2023, 15(8), 6829; https://doi.org/10.3390/su15086829 - 18 Apr 2023
Cited by 6 | Viewed by 2326
Abstract
California’s San Joaquin Valley is both drought-prone and water-scarce but relies on high-intensity agriculture as its primary economy. Climate change adaptation strategies for high-intensity agriculture require reliable and highly resolved land use classification data to accurately account for changes in crop water demand, [...] Read more.
California’s San Joaquin Valley is both drought-prone and water-scarce but relies on high-intensity agriculture as its primary economy. Climate change adaptation strategies for high-intensity agriculture require reliable and highly resolved land use classification data to accurately account for changes in crop water demand, greenhouse gas (GHG) emissions, and farmgate revenue. Understanding direct and indirect economic impacts from potential changes to high-intensity agriculture to reduce groundwater overdrafts, such as reductions in the cultivated area or switching to less water-intensive crops, is unachievable if land use data are too coarse and inconsistent or misclassified. This study quantified the revenue, crop water requirement, and GHG emission discrepancies resulting from land use misclassification in the United States’ most complex agricultural region, California’s San Joaquin Valley. By comparing three commonly used land use classification datasets—CropScape, Land IQ, and Kern County Agriculture—this study found that CropScape led to considerable revenue and crop water requirement discrepancies compared to other sources. Crop misclassification across all datasets resulted in an underestimation of GHG emissions. The total revenue discrepancies of misclassified crops by area for the 2016 dataset comparisons result in underestimations by CropScape of around USD 3 billion and overestimation by LIQ and Kern Ag of USD 72 million. Reducing crop misclassification discrepancies is essential for crafting climate resilience strategies, especially for California, which generates USD 50 billion in annual agricultural revenue, faces increasing water scarcity, and aims to reach carbon neutrality by 2045. Additional investments are needed to produce spatial land use data that are highly resolved and locally validated, especially in high-intensity agriculture regions dominated by specialty crops with unique characteristics not well suited to national mapping efforts. Full article
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13 pages, 3502 KiB  
Article
A Non-Intrusive Load Monitoring Model for Electric Vehicles Based on Multi-Kernel Conventional Neural Network
by Yanhe Yin, Baojun Xu, Yi Zhong, Tao Bao and Pengyu Wang
World Electr. Veh. J. 2023, 14(2), 51; https://doi.org/10.3390/wevj14020051 - 10 Feb 2023
Cited by 4 | Viewed by 2992
Abstract
With the widespread use of electric vehicles (EVs), the charging behavior of these resources has brought a large amount of load growth to the grid, leading to a series of problems such as increased peak valley load difference and line flow violation. Non-intrusive [...] Read more.
With the widespread use of electric vehicles (EVs), the charging behavior of these resources has brought a large amount of load growth to the grid, leading to a series of problems such as increased peak valley load difference and line flow violation. Non-intrusive load monitoring (NILM) is a key technology that can be employed to monitor the multi-source load data information in the power grid and support the high-proportion access of electric vehicles. However, traditional NILM approaches are designed to identify the operation of household appliances and cannot be applied at the substation level directly due to frequent and intricate switching events of electrical equipment at this stage. In this paper, a NILM algorithm that can be applied for the monitoring of the charging behavior of electric vehicles at the substation level is proposed to support the high-proportion injection of distributed energy resources. The proposed approach employs a deep learning framework and a multi-kernel convolutional neural network (multi-kernel CNN) framework is used. The performance of the proposed method is verified on the self-organized datasets based on Pecan Street data and results showed that the obtained f1 score is over 90% for both the training sets and testing sets. Full article
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