- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2019
- 2018
- 2015
- Photovoltaic system
- photovoltaic generation
- voltage regulation
- battery storage
- low-voltage networks
- charge – discharge energy efficiency
- Lithium-ion battery
- degradation diagnosis
- photovoltaic surplus energy
- working electric vehicle
- Electrical Engineering and Automation
- Optoelectronic Information Materials and Devices
- Optoelectronic Information Science and Engineering
- Institut Teknologi Sepuluh Nopember- ITS
- National technical University “Kharkiv Polytechnic Institute”
- State Grid Shanxi Electric Power Research Institute
- Xi’an Jiaotong University
- Zhengzhou University
- Tsinghua University
- Kuban State Agrarian University
- Cochin University College of Engineering
- University of Calgary
- Ritsumeikan University
-
Frequency‐scaled optimized time‐frequency transform for harmonic estimation in photovoltaic‐based microgrid
摘要： Renewable (especially photovoltaic [PV])‐based distributed generations (DGs) integrated via converter stations pose serious challenge against effective monitoring of fundamental and harmonic phasors because of the presence of time‐varying Nth‐order harmonics, which get escalated in terms of voltage flicker, total harmonics distortion profiles with increased penetration level of such renewable sources. The generalized S‐transform (ST) has been used extensively for these nonstationary power signals analysis because it localizes the signal spectrum in time and yields a phase spectrum also for obtaining both amplitude and phase characteristics. However, the transform suffers from large execution time and arbitrary choice of window parameters. The paper, therefore, presents a new approach to extract time‐frequency response (TFR) from a harmonically scaled Fourier kernel ST optimized by metaheuristic firefly algorithm suitable for monitoring of microgrid phasors in real time, which can be ultimately used for effective power management and coordination. This new formulation uses selective frequency scaling to achieve a significant time reduction (within a half cycle of the initiation of the disturbance) in monitoring and tracking time‐varying harmonic disturbances, especially for DG‐integrated operations. Extensive simulation results for monitoring of time‐varying fundamental and harmonics in PV‐based grid‐connected power networks are presented against efficacy measures. Further, to validate in real time, a TMS320 C6713 digital signal processor (DSP) test bench is included in the paper for fundamental and harmonics estimation.
关键词： monitoring,photovoltaic,filtering,nonstationary power signal,harmonics,scaling methods,real‐time S‐transform
更新于2025-09-11 14:15:04
-
Accelerating the Screening of Perovskite Compositions for Photovoltaic Applications through High‐Throughput Inkjet Printing
摘要： The exploration and optimization of numerous mixed perovskite compositions are causing a strong demand for high-throughput synthesis. Nevertheless high-throughput fabrication of perovskite films with representative film properties, which can efficiently screen the perovskite compositions for photovoltaic applications, has rarely been explored. A high-throughput inkjet printing approach that can automatically fabricate perovskite films with various compositions with high reproducibility and high speed is developed. The automatic sequential printing of four precursors forms 25 mixed films in a fast and reproducible manner. The obtained bandgaps, photoluminescence (PL) peak positions, and PL lifetimes allow for the efficient screening of perovskite compositions for photovoltaic applications. To exemplify this concept, among 25 tested films, two compositions CH3NH3PbBr0.75I2.25 (MA) and (HC(NH2)2)0.75(CH3NH3)0.25PbBr0.75I2.25 (FA0.75MA0.25) with a long (237 ns) and short (49.0 ns) PL lifetime, respectively, are screened out for device investigations. As expected, the MA-based device exhibits a much higher efficiency (19.0%) than that (15.3%) of the FA0.75MA0.25 counterpart. This efficiency improvement is mainly ascribed to a smaller dark saturate current density, a lower level of energetic disorder, more efficient charge transfer and decreased charge recombination losses, which are consistent with the much longer PL lifetime in the database.
关键词： perovskites,photovoltaic applications,inkjet printing,high throughput fabrication
更新于2025-09-11 14:15:04
-
An optimal switching approach toward cost‐effective control of a stand‐alone photovoltaic panel system under stochastic environment
摘要： The operation of a stand-alone photovoltaic (PV) system ultimately aims for the optimization of its energy storage. We present a mathematical model for cost-effective control of a stand-alone system based on a PV panel equipped with an angle adjustment device. The model is based on viscosity solutions to partial differential equations, which serve as a new and mathematically rigorous tool for modeling, analyzing, and controlling PV systems. We formulate a stochastic optimal switching problem of the panel angle, which is here a binary variable to be dynamically controlled under stochastic weather condition. The stochasticity comes from cloud cover dynamics, which is modeled with a nonlinear stochastic differential equation. In finding the optimal control policy of the panel angle, switching the angle is subject to impulsive cost and reduces to solving a system of Hamilton-Jacobi-Bellman quasi-variational inequalities (HJBQVIs). We show that the stochastic differential equation is well posed and that the HJBQVIs admit a unique viscosity solution. In addition, a finite-difference scheme is proposed for the numerical discretization of HJBQVIs. A demonstrative computational example of the HJBQVIs, with emphasis on a stand-alone experimental system, is finally presented with practical implications for its cost-effective operation.
关键词： stochastic optimal switching,cloud cover dynamics,Hamilton-Jacobi-Bellman quasi-variational inequalities (HJBQVIs),stand-alone photovoltaic system
更新于2025-09-11 14:15:04
-
Techno‐economic assessment of solar photovoltaic integration into national grids: A case study of Burkina Faso
摘要： To promote a low‐carbon society, it is urgent to better integrate renewable energies into energy supply systems. This paper examines the impact of solar photovoltaic (PV) integration into the national electrical grid in Burkina Faso on the electricity production cost. The analysis is based on the levelized cost of electricity (LCOE) technique. Several levels of PV integration have been considered namely 20%, 40%, 60%, and 80% of the total installed capacity. First, the results revealed all the configurations with PV integration are more attractive and cost‐effective compared with the conventional diesel standalone electricity system. The sensitivity analysis shows that the configuration with 80% PV is the most attractive when compared to the other ones as it has the lowest LCOE and CO2 emissions compared with the other scenarios. This paper also shows that in the context of rising fuel prices and environmental concern, the electricity production based on diesel standalone system is not a viable solution for Burkina Faso at the moment. Finally, the results revealed that subsidies offered by the government of Burkina Faso to support the electricity production cost will be more effective for a system with PV integration. This paper gives detail highlights of solution for policymakers to make useful investment in solar energy and widen the access to electricity in Burkina Faso.
关键词： Burkina Faso,optimization,solar photovoltaic,levelized cost of electricity,diesel generator,grid integration
更新于2025-09-11 14:15:04
-
AIP Conference Proceedings [AIP Publishing 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Fes, Morocco (25–27 March 2019)] 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) - Finite element analysis of cooling mechanism by flat heat-sinks in ultra-high CPV systems
摘要： The potential cost reduction of Concentrator photovoltaic (CPV) systems is closely related to the concentration factor because higher light concentrations imply lower amount of semiconductor material required for the solar cells. However, the thermal management at such ultra-high light fluxes is difficult. The use of small-sized solar cells is beneficial for improving the thermal management. Among the possible cooling strategies, the use of flat-plate heat-sinks for passive cooling, if feasible, would be the simplest way to dissipate heat and would accelerate the development of ultra-high CPV prototypes. In this work, a thermal 3D finite-element model is used to investigate the possibilities of flat-plate heat-sinks for passive cooling at concentration ratios within 2,000-10,000 suns. Results show that a micro solar cells of 1mm x 1mm area can be thermally handled with conventional Aluminium flat plate heat-sinks up to 10,000 suns.
关键词： ultra-high concentration,passive cooling,Concentrator photovoltaic (CPV),thermal management,flat-plate heat-sinks
更新于2025-09-11 14:15:04
-
[IEEE 2019 IEEE International Conference on Automatic Control and Intelligent Systems (I2CACIS) - Selangor, Malaysia (2019.6.29-2019.6.29)] 2019 IEEE International Conference on Automatic Control and Intelligent Systems (I2CACIS) - Limiting THD of Grid Connected Photovoltaic System using PWM Switching Frequency Selection Based on Solar Irradiance Changing
摘要： Photovoltaic (PV) system becomes the best alternative energy to produce electricity that can replace fuel resource. Grid Connected Photovoltaic (GC-PV) system will supply the AC power generated to the utility grid then distributed to the consumer. Solar irradiance in Malaysia varies daily and throughout the year. The consequence of low irradiance level is the output of the PV array is low and thus the input of the inverter relatively becoming low. The inverter will exhibit large non-linearity when the inverter is operating at low power input during low level of solar irradiance and Total Harmonic Distortion (THD) will increased. Pulse Width Modulation (PWM) techniques that are Continuous Pulse Width Modulation (CPWM) and Discontinuous PWM (DPWM) are implemented in the inverter control of the GC-PV system using MATLAB/Simulink environment to investigate the effect of switching frequency on THD at different level of solar irradiance. THD is limit within standard requirement by selecting appropriate value of switching frequency. Results shows that CPWM has better performance in THD and switching losses at selected switching frequency.
关键词： total harmonic distortion,inverter,pulse width modulation,switching frequency,grid connected photovoltaic,solar irradiance
更新于2025-09-11 14:15:04
-
Influences of buffer material and fabrication atmosphere on the electrical properties of CdTe solar cells
摘要： The electrical properties such as interface energy barriers, defect energy levels, and densities dictate the performance of thin film solar cells. Here, we show that these properties can be quantified in cadmium telluride (CdTe) thin‐film solar cells using admittance spectroscopy‐based techniques. Our results reveal that the electrical properties in CdTe thin‐film solar cells depend on both buffer material and the fabrication atmosphere. We find that only a negligible front contact barrier exists at the CdS/CdTe front junction regardless of the fabrication atmospheres, while an obvious front barriers are observed at the ZnMgO (ZMO)/CdTe junctions. Both CdS/CdTe and ZMO/CdTe solar cells exhibit back contact barrier. The energy level of defects is shallower in CdS/CdTe cells than in ZMO/CdTe cells. The fabrication atmosphere influences the electrical properties, i.e., an oxygen‐free atmosphere reduces the front and back barrier heights and lowers the energy level of defects. The results provide critical insights for understanding and optimizing the performance of CdTe thin‐film solar cells.
关键词： admittance spectroscopy,interface barriers,cadmium telluride,equivalent circuit,photovoltaic cells
更新于2025-09-11 14:15:04
-
[IEEE 2019 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) - Auckland, New Zealand (2019.5.20-2019.5.23)] 2019 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) - Calculating the Output Power of Photovoltaic Cells on Top of Electric and Hybrid Electric Vehicles
摘要： This paper investigates the potential output power of a photovoltaic (PV) installation on top of battery-powered electric vehicles (BEVs) and hybrid electric vehicles (HEVs). Firstly, we discuss the available area on the roof of BEVs and HEVs for deploying PV cells. Secondly, we verify the impact of the curved surface on the available output power of photovoltaics. Furthermore, we discuss the impact of the curved surface and the ambient conditions on the possible alignment of PV cells. Here, we present a method of calculating the effective area of PV cells, useful for PV simulation models and calculating the available output power of PV cells with different longitudinal angles. Finally, we verify our method within experiments and present the results of them, showing that the model predicts the output power of PV cells with an accuracy better than 2.5%.
关键词： data acquisition,solar energy,environmental data,simulation,battery-powered electric vehicle,photovoltaic energy,measurement,hybrid electric vehicle
更新于2025-09-11 14:15:04
-
Improved Charge Pump Design and $Ex\ Vivo$ Experimental Validation of CMOS 256-Pixel Photovoltaic-Powered Subretinal Prosthetic Chip
摘要： An improved design of a 256-pixel photovoltaic-powered implantable chip for subretinal prostheses is presented. In the proposed subretinal chip, a high-efficiency fully-integrated 4× charge pump is designed and integrated with on-chip photovoltaic (PV) cells and a 256-pixel array with active pixel sensors (APS) for image light sensing, biphasic constant current stimulators, and electrodes. Thus the PV voltage generated by infrared (IR) light can be boosted to above 1V so that the charge injection is increased. The proposed chip adopts the 32-phase divisional power supply scheme (DPSS) to reduce the required supply current and thus the required area of the PV cells. The proposed chip is designed and fabricated in 180-nm CMOS technology and post-processed with image sensor biocompatible IrOx electrodes and silicone packaging. From the electrical measurement results, the measured stimulation frequency is 28.3 Hz under the equivalent electrode impedance load. The measured maximum output stimulation current is 7.1 μA and the amount of injected charges per pixel is 7.36 nC under image light intensity of 3200 lux and IR light intensity of 100 mW/cm2. The function of the proposed chip has been further validated successfully with the ex vivo experimental results by recording the electrophysiological responses of retinal ganglion cells (RGCs) of retinas from retinal degeneration (rd1) mice with a multi-electrode array (MEA). The measured average threshold injected charge is about 3.97 nC which is consistent with that obtained from the patch clamp recording on retinas from wild type (C57BL/6) mice with a single electrode pair.
关键词： biocompatible package,divisional power supply scheme,multi-electrode array,charge pump,photovoltaic cell
更新于2025-09-11 14:15:04
-
Prediction of sunlight-driven CO2 conversion: Producing methane from photovoltaics, and full system design for single-house application
摘要： CO2 capture and utilization (CCU) technologies are being immensely researched as means to close the anthropogenic carbon cycle. One approach known as artificial photosynthesis uses solar energy from photovoltaics (PV), carbon dioxide and water to generate hydrocarbon fuels, being methane (CH4) a preferential target due to the already in place infrastructures for its storage, distribution and consumption. Here, a model is developed to simulate a direct (1-step) solar methane production approach, which is studied in two scenarios: first, we compare it against a more conventional 2-step methane production route, and second, we apply it to address the energetic needs of concept buildings with usual space and domestic hot water heating requirements. The analysed 2-step process consists in the PV-powered synthesis of an intermediate fuel e syngas e followed by its conversion to CH4 via a Fischer eTropsch (methanation) process. It was found that the 1-step route could be adequate to a domestic, small scale use, potentially providing energy for a single-family house, whilst the 2-step can be used in both small and large scale applications, from domestic to industrial uses. In terms of overall solar-to-CH4 energy efficiency, the 2-step method reaches 13.26% against the 9.18% reached by the 1-step method. Next, the application of the direct solar methane technology is analysed for domestic buildings, in different European locations, equipped with a combination of solar thermal collectors (STCs) and PV panels, in which the heating needs that cannot be fulfilled by the STCs are satisfied by the combustion of methane synthesized by the PV-powered electrolyzers. Various combinations of situations for a whole year were studied and it was found that this auxiliary system can produce, per m2 of PV area, in the worst case scenario 23.6 g/day (0.328 kWh/day) of methane in Stockholm, and in the best case scenario 47.4 g/day (0.658 kWh/day) in Lisbon.
关键词： Artificial photosynthesis,Fischer-Tropsch synthesis,Photovoltaic-powered electrochemical conversion,Building-integrated solar methane,CO2 electrolysis
更新于2025-09-11 14:15:04