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- 摘要
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- 实验方案
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Techno‐economic analysis of applying linear parabolic and flat plate solar collectors for heating a building and their comparative evaluation
摘要： In this study, utilizing two types of solar collectors, including linear parabolic (LPC) and flat solar (FPC) collectors to heat a residential building was investigated from technical and economical point of views. The performance of these two systems were obtained and compared with each other in the cold months of the year in the South-East of Iran. The building and the heating systems were simulated in the TRNSYS software. Both the heating systems were separately analyzed from the energy and economic point of views. Results showed that the FPC and LPC heating systems delivered 51.3% and 46.7% of the received solar energy to the building, respectively. The results also showed that the solar fractions of the LPC and FPC heating systems are 22% and 8.6%, respectively. It was found that the thermal storage tank in the FPC hearing system is more useful than the LPC heating system as the LPC heating system with storage tank has a lower rate of heat loss compared to the system with no thermal storage tank. The rate of return investments in the FPC and LPC heating systems were 18.1% and 22.8%, respectively.
关键词： economic analysis,linear parabolic collectors (LPC),TRNSYS,heating load,flat plate collector (FPC),solar heating
更新于2025-09-19 17:15:36
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Photovoltaic Module Reliability || Development of Accelerated Stress Tests
摘要： The chapter discusses the development of accelerated stress tests (ASTs) for photovoltaic (PV) modules to identify and mitigate field failure modes. It outlines various ASTs such as Thermal Cycling, Damp Heat, Humidity Freeze, UV Light Exposure, Static Mechanical Load, Cyclic (Dynamic) Mechanical Load, Reverse Bias Hot Spot Test, Bypass Diode Thermal Test, and Hail Test, detailing their parameters and the failure modes they address. The importance of ASTs in improving module reliability and lifetime is emphasized, along with the challenges in accelerating certain processes without altering the failure mechanisms.
关键词： Reverse Bias Hot Spot Test,UV Light Exposure,Damp Heat,Static Mechanical Load,Hail Test,Thermal Cycling,Photovoltaic Module Reliability,Accelerated Stress Tests,Humidity Freeze,Bypass Diode Thermal Test,Cyclic (Dynamic) Mechanical Load
更新于2025-09-19 17:13:59
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[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Synchronous Pumping Terahertz Parametric Oscillator Driven by Amplified Picosecond Mode-locked Laser
摘要： This paper analyzes the effects of load impedance mismatch in power ampli?ers which linearity has been enhanced using various digital predistortion (DPD) algorithms. Two different power ampli?er architectures are considered: a class AB and a Doherty ampli?er and three model structures for the DPD model are compared: memoryless polynomial (MLP), general memory polynomial (GMP) and Kautz-Volterra functions (KV). This paper provides a sensitivity analysis of the linearized ampli?ers under load mismatch conditions and reports the performance when dynamic parameter identi?cation for the DPD is used to compensate for the changes in the load impedance. In general, power ampli?ers linearity is sensitive to load impedance mismatch. Linearity may degrade as much as 10 dB (in normalized mean square error) according to the magnitude and the phase of the re?ection coef?cient provided by the load impedance. However, depending on the ampli?er design, the sensitivity to load impedance mismatch varies. While the Doherty ampli?er studied show signi?cant linearity degradations in the in-band and out-of-band distortions, the out-of-band distortions of the studied class AB were less sensitive to the load impedance mismatch. In adaptive DPD schemes, the performance obtained in the MLP model does not bene?t from the updating scheme and the performance achieved is similar to a static case, where no updates are made. This stresses the memory requirements in the predistorter. When employing the GMP and the KV models in an adaptive DPD scheme, they tackle to a larger extent the linearity degradations due to load impedance mismatch.
关键词： load impedance,Digital predistortion,power ampli?ers,impedance mismatch
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE Research and Applications of Photonics in Defense Conference (RAPID) - Miramar Beach, FL, USA (2019.8.19-2019.8.21)] 2019 IEEE Research and Applications of Photonics in Defense Conference (RAPID) - Invited Talk: "High Resolution Space/Time Imaging of Shockwaves Generated by Remote Laser Plasmas Produced by Light Filaments"
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： PCA,dimensionality reduction,electric load prediction,smart grid,genetic algorithm,forecasting,echo state network,Time-series
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Quantum Temporal Imaging with Finite Time Aperture
摘要： Balancing electricity supply and demand is a complex task. Renewable energy sources are often intermittent, while electrical loads vary throughout the day. This can result in an abundant supply that suppresses spot prices in one region, while another region simultaneously experiences tight supply margins and price spikes. Connecting these two regions through electrical interconnectors would enable greater utilization of renewable energy, but this can be expensive and is unfeasible for distant regions, such as between continents. However, datacenters are becoming ubiquitous around the world and are linked through fiber connections. This paper proposes a virtual interconnector (VIC) scheme using fiber to dynamically move energy demand, in the form of computation, to datacenters in other market regions with surplus low cost and renewable energy. This increases the global renewable penetration without requiring expensive grid interconnections. The associated benefits for the datacenter operator, the electricity grid controller, consumers, and the environment are discussed.
关键词： power system economics,load management,optical interconnections,power system control,Data warehouses,renewable energy sources,green computing,power system interconnection
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) - Design of a multi - wavelength high irradiance LED phototherapy system for LLLT
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,visually impaired,haptics,Assistive device,performance,behavior,gender,visual experience
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Fundamental Design Principles for Reflective Membranes in Thermal Noise Limited Cavities
摘要： In wireless sensor networks (WSNs), the base station (BS) is a critical sensor node whose failure causes severe data losses. Deploying multiple fixed BSs improves the robustness, yet requires all BSs to be installed with large batteries and large energy-harvesting devices due to the high energy consumption of BSs. In this paper, we propose a scheme to coordinate the multiple deployed BSs such that the energy supplies required by individual BSs can be substantially reduced. In this scheme, only one BS is selected to be active at a time and the other BSs act as regular sensor nodes. We first present the basic architecture of our system, including how we keep the network running with only one active BS and how we manage the handover of the role of the active BS. Then, we propose an algorithm for adaptively selecting the active BS under the spatial and temporal variations of energy resources. This algorithm is simple to implement but is also asymptotically optimal under mild conditions. Finally, by running simulations and real experiments on an outdoor testbed, we verify that the proposed scheme is energy-efficient, has low communication overhead and reacts rapidly to network changes.
关键词： energy efficiency,communication,Wireless sensor networks,renewable load management,cooperative energy sources
更新于2025-09-19 17:13:59
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Solar Engineering of Thermal Processes, Photovoltaics and Wind || Design of Passive and Hybrid Heating Systems
摘要： The principles underlying passive (and active) solar processes are outlined in Chapters 1 to 11, and passive heating and cooling processes and phenomena associated with them are described in Chapters 14 and 15. In this chapter we deal with questions of estimating the annual performance of several types of passive building-heating systems. The solar-load ratio correlation method developed at Los Alamos Scientific Laboratory is first introduced. The application of utilizability methods to direct-gain and collector-storage wall systems is shown. Then design methods for two hybrid systems are outlined, for active collection–passive storage systems and for systems having significant fractions of annual loads carried by both active and passive processes. This combination of methods will allow the annual performance of a wide variety of passive and hybrid systems to be estimated.
关键词： utilizability methods,solar-load ratio,passive solar heating,hybrid systems,annual performance
更新于2025-09-19 17:13:59
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Conceptual design of a conduction cooled superconducting undulator
摘要： In superconducting undulators (SCUs) that are currently operating at the Advanced Photon Source, the undulator magnets are indirectly cooled with liquid helium penetrating through channels in the magnet cores. The liquid helium is stored in a tank that is cooled by cryocoolers. However, a cryogen-free version of a superconducting undulator in which the undulator magnets are conduction-cooled is also possible, as has been realized in the SCUs developed at ANKA. We are currently working on a conceptual design of a conduction-cooled planar superconducting undulator. The measured load lines of cryocoolers and the measured thermal conductance of various thermal links are used in the thermal analysis. Also, various materials for the undulator magnet cores are being considered. This paper reports the thermal design of a conduction-cooled planar SCU.
关键词： load map,cryocooler,thermal conductance,thermal contraction,superconducting undulator
更新于2025-09-19 17:13:59
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Optimal Design of Standalone Photovoltaic System Based on Multi-Objective Particle Swarm Optimization: A Case Study of Malaysia
摘要： This paper presents a multi-objective particle swarm optimization (MOPSO) method for optimal sizing of the standalone photovoltaic (SAPV) systems. Loss of load probability (LLP) analysis is considered to determine the technical evaluation of the system. Life cycle cost (LCC) and levelized cost of energy (LCE) are treated as the economic criteria. The two variants of the proposed PSO method, referred to as adaptive weights PSO (AWPSOc f ) and sigmoid function PSO (SFPSOc f ), are implemented using MATLAB software to the optimize the number of PV modules in (series and parallel) and number of the storage battery. The case study of the proposed SAPV system is executed using the hourly meteorological data and typical load demand for one year in a rural area in Malaysia. The performance outcomes of the proposed AW/SFPSOc f methods give various con?gurations at desired levels of LLP values and the corresponding minimum cost. The performance results showed the superiority of SFPSOc f in terms of accuracy is selecting an optimal con?guration at ?tness function value 0.031268, LLP value 0.002431, LCC 53167 USD, and LCE 1.6413 USD. The accuracy of AW/SFPSOc f methods is veri?ed by using the iterative method.
关键词： levelized cost of energy (LCE),multi-objective optimization,particle swarm optimization,standalone PV system,loss of load probability (LLP),life cycle cost (LCC)
更新于2025-09-19 17:13:59