- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) - Sydney, Australia (2018.11.10-2018.11.17)] 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference Proceedings (NSS/MIC) - Large Area Picosecond Photodetector (LAPPD) Performance Test Results
摘要： In this paper, we consider a network in which lower power nodes (LPNs) are deployed jointly within macrocells. However, there are significant differences between the transmit power levels, coverage areas, and deployment densities of these two types of base stations. Such disparities lead to an unfair load distribution, as well as a lower throughput for picocells’users equipments (UEs). A good solution to such issues is the exploitation of the cell range expansion (CRE) technique. Although CRE has widely proven its effectiveness, it may degrade the network capacity if the cell bias is not chosen properly. In fact, it may generate severe intercell interference at extended region cell (ERC) UEs, which leads to a deterioration of their throughput. We thus propose a downlink coordinated cell range expansion for mobility management (CCREMM) strategy that analytically computes the joint optimal bias at picocells and macrocells. CCREMM mitigates the interference at ERC-UEs by accounting for their maximum tolerable interference. Moreover, CCREMM reaches the load balancing and the UE QoS satisfaction by accounting for additional parameters. It will be proven that our strategy which is associated with the maximum throughput scheduling technique, results in a cell load-balancing improvement, fairness, and a 50–90% UE throughput enhancement. These performance figures are shown to surpass those achieved by alternative approaches proposed in the existing literature.
关键词： HetNets,load balancing,QoS,resource allocation,mobility management
更新于2025-09-19 17:13:59
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Sunny with a chance of curtailment: Operating the U.S. grid with very high levels of solar photovoltaics
摘要： With rapid declines in solar photovoltaic (PV) and energy storage costs, futures with PV penetrations approaching or exceeding 50% of total annual U.S. generation are becoming conceivable. The operational merits of such a national-scale system have not been evaluated sufficiently. Here, we analyze in detail the operational impacts of a future U.S. power system with very high annual levels of PV (>50%) with storage. We show that load and operating reserve requirements can be met for all hours while considering key generator operational constraints. Storage plays an active role in maintaining the balance of supply and demand during sunset hours. Under the highest PV penetration scenario, hours with >90% PV penetration are relatively common, which require rapid transitions between predominately conventional synchronous generation and mostly inverter-based generation. We observe hours with almost 400 GW (over 40%) of economic curtailment and frequent (up to 36%) hours with very low energy prices.
关键词： Photovoltaic generation,energy storage,net load,renewables,energy prices,solar energy,thermal cycling,curtailment,production cost modeling,ramping
更新于2025-09-19 17:13:59
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[IEEE 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Shenzhen, China (2019.11.25-2019.11.27)] 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Research on a Smart LED Lighting Based on Improved Flyback Driver
摘要： In this paper, we approach the problem of forecasting a time series (TS) of an electrical load measured on the Azienda Comunale Energia e Ambiente (ACEA) power grid, the company managing the electricity distribution in Rome, Italy, with an echo state network (ESN) considering two different leading times of 10 min and 1 day. We use a standard approach for predicting the load in the next 10 min, while, for a forecast horizon of one day, we represent the data with a high-dimensional multi-variate TS, where the number of variables is equivalent to the quantity of measurements registered in a day. Through the orthogonal transformation returned by PCA decomposition, we reduce the dimensionality of the TS to a lower number k of distinct variables; this allows us to cast the original prediction problem in k different one-step ahead predictions. The overall forecast can be effectively managed by k distinct prediction models, whose outputs are combined together to obtain the final result. We employ a genetic algorithm for tuning the parameters of the ESN and compare its prediction accuracy with a standard autoregressive integrated moving average model.
关键词： genetic algorithm,forecasting,PCA,echo state network,Time-series,smart grid,electric load prediction,dimensionality reduction
更新于2025-09-19 17:13:59
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[IEEE 2017 IEEE 44th Photovoltaic Specialists Conference (PVSC) - Washington, DC (2017.6.25-2017.6.30)] 2017 IEEE 44th Photovoltaic Specialist Conference (PVSC) - High built-in potential and Voc of monocrystalline CdTe/MgCdTe double-heterostructure solar cells with p-type a-Si:H hole-contacts
摘要： Tactile maps are efficient tools to improve spatial understanding and mobility skills of visually impaired people. Their limited adaptability can be compensated with haptic devices which display graphical information, but their assessment is frequently limited to performance-based metrics only which can hide potential spatial abilities in O&M protocols. We assess a low-tech tactile mouse able to deliver three-dimensional content considering how performance, mental workload, behavior, and anxiety status vary with task difficulty and gender in congenitally blind, late blind, and sighted subjects. Results show that task difficulty coherently modulates the efficiency and difficulty to build mental maps, regardless of visual experience. Although exhibiting attitudes that were similar and gender-independent, the females had lower performance and higher cognitive load, especially when congenitally blind. All groups showed a significant decrease in anxiety after using the device. Tactile graphics with our device seems therefore to be applicable with different visual experiences, with no negative emotional consequences of mentally demanding spatial tasks. Going beyond performance-based assessment, our methodology can help with better targeting technological solutions in orientation and mobility protocols.
关键词： cognitive load,haptics,Assistive device,gender,visually impaired,visual experience,performance,behavior
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - High Efficiency non-toxic CuSbS <sub/>2</sub> -based Heterojunction Solar Cell with TiO <sub/>2</sub> Electron Transport Layer
摘要： Tactile maps are efficient tools to improve spatial understanding and mobility skills of visually impaired people. Their limited adaptability can be compensated with haptic devices which display graphical information, but their assessment is frequently limited to performance-based metrics only which can hide potential spatial abilities in O&M protocols. We assess a low-tech tactile mouse able to deliver three-dimensional content considering how performance, mental workload, behavior, and anxiety status vary with task difficulty and gender in congenitally blind, late blind, and sighted subjects. Results show that task difficulty coherently modulates the efficiency and difficulty to build mental maps, regardless of visual experience. Although exhibiting attitudes that were similar and gender-independent, the females had lower performance and higher cognitive load, especially when congenitally blind. All groups showed a significant decrease in anxiety after using the device. Tactile graphics with our device seems therefore to be applicable with different visual experiences, with no negative emotional consequences of mentally demanding spatial tasks. Going beyond performance-based assessment, our methodology can help with better targeting technological solutions in orientation and mobility protocols.
关键词： cognitive load,haptics,Assistive device,gender,visually impaired,visual experience,performance,behavior
更新于2025-09-19 17:13:59
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[IEEE 2019 4th International Conference on Mechanical, Control and Computer Engineering (ICMCCE) - Hohhot, China (2019.10.24-2019.10.26)] 2019 4th International Conference on Mechanical, Control and Computer Engineering (ICMCCE) - Video Based Fire Detection in Photovoltaic System
摘要： This paper presents a novel energy-management method for a microgrid that includes renewable energy, diesel generators, battery storage, and various loads. We assume that the microgrid takes part in a pool market and responds actively to the electricity price to maximize its profit by scheduling its controllable resources. To address various uncertainties, a risk-constrained scenario-based stochastic programming framework is proposed using the conditional value at risk method. The designed model is solved by two levels of stochastic optimization methods. One level of optimization is to submit optimal hourly bids to the day-ahead market under the forecast data. The other level of optimization is to determine the optimal scheduling using the scenario-based stochastic data of the uncertain resources. The proposed energy management system is not only beneficial for the microgrid and customers, but also applies the microgrid aggregator and virtual power plant. The results are shown to prove the validity of the proposed framework.
关键词： energy management,Controllable load,stochastic optimization,microgrid,risk management,smart grid,renewable energy,electricity market
更新于2025-09-19 17:13:59
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New monitoring method to characterize individual modules in large photovoltaic systems
摘要： Photovoltaic (PV) systems power losses are approximately 15–20% of the performance ratio for current PV systems. There are several reasons that explain PV modules failures, and since they are connected in series to the rest of the string, a failure in one module may result in losses in the entire string. In addition, some of these failures, if are not fixed in time may become permanent and may reduce the lifespan of the PV modules. Periodic monitoring is the only way to detect these failures. Monitoring techniques oriented to groups of modules are unable to detect faults in individual modules. I-V curve tracers, which are oriented to module level and use power electronics components and large capacitors, require to disconnect the PV module from the rest of the system and long measurement times. This works proposes a methodology, that is able to take partial measurements of individual PV modules and recompose their characteristics with only small capacitors in the range of tens of microfarads and without power electronics components. The monitoring methodology is able to measure individual PV modules without modifying the electrical interconnection circuit and to deviate the operating point to 0.3 A and 5 V in less than 5 ms. From this deviation, the system recomposes the PV module I-V characteristics with accuracies that are between 1 and 3% for the region close to maximum power.
关键词： Monitoring,Fault detection,Photovoltaic systems,Capacitive load,Maximum power point
更新于2025-09-19 17:13:59
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[IEEE 2018 11th UK-Europe-China Workshop on Millimeter Waves and Terahertz Technologies (UCMMT) - HangZhou, China (2018.9.5-2018.9.7)] 2018 11th UK-Europe-China Workshop on Millimeter Waves and Terahertz Technologies (UCMMT) - Development of Millimeter-Band Folded-Waveguide Slow-Wave Structures for a High-Power Traveling-Wave Tube Amplifier
摘要： With ongoing large-scale smart energy metering deployments worldwide, disaggregation of a household’s total energy consumption down to individual appliances using analytical tools, also known as non-intrusive appliance load monitoring (NALM), has generated increased research interest lately. NALM can deepen energy feedback, support appliance retrofit advice, and support home automation. However, despite the fact that NALM was proposed over 30 years ago, there are still many open challenges with respect to its practicality and effectiveness at low sampling rates. Indeed, the majority of NALM approaches, supervised or unsupervised, require training to build appliance models, and are sensitive to appliance changes in the house, thus requiring regular re-training. In this paper, we tackle this challenge by proposing an NALM approach that does not require any training. The main idea is to build upon the emerging field of graph signal processing to perform adaptive thresholding, signal clustering, and pattern matching. We determine the performance limits of our approach and demonstrate its usefulness in practice. Using two open access datasets—the US REDD data set with active power measurements downsampled to 1 min resolution and the UK REFIT data set with 8-s resolution, we demonstrate the effectiveness of the proposed method for typical smart meter sampling rate, with the state-of-the-art supervised and unsupervised NALM approaches as benchmarks.
关键词： graph signal processing,load disaggregation,Non-intrusive appliance load monitoring
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE PES Innovative Smart Grid Technologies Europe (ISGT-Europe) - Bucharest, Romania (2019.9.29-2019.10.2)] 2019 IEEE PES Innovative Smart Grid Technologies Europe (ISGT-Europe) - Probabilistic Assessment of Photovoltaic Hosting Capacity in Finnish LV Networks
摘要： Large number of photovoltaic (PV) installations can lead to the network constraints’ violations that comprise the voltage level outside the statutory limits and equipment ampacity-limit violations. This study quantifies the hosting capacities (HCs) of the Finnish LV networks and their limiting constraints. A stochastic approach is implemented to cover all the probabilistic variables of the LV network. Geographically distinct LV networks of rural, intermediate and urban regions are studied with the balanced and unbalanced PV feed-in scenarios. Later, the HC enhancement potential of various auxiliary equipment and techniques, like the battery storage, on-load tap changer (OLTC), network reinforcement and reactive power control of inverters, is determined. Moreover, the effect of different country-specific voltage level standards’ implementation and the commercially available OLTC employment are also studied with varying PV penetrations.
关键词： Hosting capacity,On-load tap changer,Low voltage networks,Photovoltaics
更新于2025-09-16 10:30:52
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[IEEE 2019 International Ural Conference on Electrical Power Engineering (UralCon) - Chelyabinsk, Russia (2019.10.1-2019.10.3)] 2019 International Ural Conference on Electrical Power Engineering (UralCon) - Development of Method for Photovoltaic Generation Control by Electrical Network Relative Power Losses Minimization Criteria
摘要： In recent years, the world practice shows that in many developed countries the use of renewable energy sources has become an important factor for the sustainable development of their energy sector. The integration of solar power plants into the electric networks is one of the most important directions for the development of energy, but the issue of the influence of solar generation on the modes of electric distribution networks and the relative power loss is acute. This paper analyzes the effect of distributed solar generation on power losses and the configuration of the load curve. The problem of excessive solar generation at the weekend causes the flow of active power from the consumer to the power system, which leads to a change in the configuration of the load curve and an increase in the relative power losses. A calculation method is proposed to minimize relative power losses in electric networks, which allows improving the efficiency of the electric grid company in the conditions of integration of distributed solar generation. Also, to confirm the correctness of the calculation results of the proposed method, variational calculations were carried out.
关键词： Shape factor,Power losses,Load curve,Republic of Tajikistan,Solar generation
更新于2025-09-16 10:30:52