scholarly journals Modelling Properties of an Alkaline Electrolyser

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3073
Author(s):  
Krzysztof Górecki ◽  
Małgorzata Górecka ◽  
Paweł Górecki
Keyword(s):  
Potassium Hydroxide ◽  
Dynamic Properties ◽  
Operating Conditions ◽  
High Productivity ◽  
Electrolysis Process ◽  
Average Value ◽  
Current Voltage ◽  
Wide Range ◽  
Current Voltage Characteristics ◽  
Parameter Values

This paper proposes a model of an electrolyser in the form of a subcircuit dedicated for SPICE. It takes into account both the electric static and dynamic properties of the considered device and is devoted to the optimisation of the parameters of the signal feeding this electrolyser, making it possible to obtain a high productivity and efficiency of the electrolysis process. Parameter values the describing current-voltage characteristics of the electrolyser take into account the influence of the concentration of the potassium hydroxide (KOH) solution. A detailed description of the structure and all the components of this model is included in the paper. The correctness of the elaborated model is verified experimentally in a wide range of changes in the value of the feeding current and concentration of the KOH solution. Some computations illustrating the influence of the amplitude, average value, duty factor, and frequency of feeding current on the productivity and efficiency of the electrolysis process are performed. On the basis of the obtained results of the investigations, some recommendations for the operating conditions of electrolysers are formulated.

Simulation of Freeway Weaving Areas

2002 ◽  
Vol 1802 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Alexander Skabardonis
Keyword(s):  
Operating Conditions ◽  
Model Parameters ◽  
Sensitivity Factor ◽  
Microscopic Simulation ◽  
Lane Changing ◽  
Wide Range ◽  
Design Characteristics ◽  
Predicted Values ◽  
Demand Patterns ◽  
Parameter Values

The operation of freeway weaving sections is characterized by intense lane-changing maneuvers and complex vehicle interactions that often create bottlenecks along freeway facilities. The CORSIM microscopic simulation model was applied to simulate the operation of eight realworld weaving sites in California under a wide range of operating conditions. The results indicate that CORSIM with default parameter values underpredicts the speeds in the weaving section by about 19% on average. Numerous simulation runs were made with different values of the model parameters. The following parameters were found to significantly affect the CORSIM results: ( a) car-following sensitivity factor, ( b) lane-changing aggressiveness factor, and ( c) percentage of freeway through vehicles that yield to merging traffic. The calibrated CORSIM model reasonably replicated observed traffic operations at all test sites. The predicted average speeds were within ±5 mph for most test sites. Good agreement between measured and predicted values was obtained for all the combinations of design characteristics and demand patterns.

Simulation of Hydrogenated Amorphous Silicon Germanium Alloys for Bandgap Grading

1999 ◽  
Vol 557 ◽  
Author(s):  
E. Schroten ◽  
M. Zeman ◽  
R. A. C. M. M. van Swaaij ◽  
L. L. A. Vosteen ◽  
J. W. Metselaar
Keyword(s):  
Amorphous Silicon ◽  
Material Properties ◽  
Silicon Germanium ◽  
Hydrogenated Amorphous Silicon ◽  
Model Parameters ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Amorphous Silicon Germanium ◽  
Parameter Values ◽  
Hydrogenated Amorphous

AbstractComputer simulations are reported of hydrogenated amorphous silicon germanium (a-SiGe:H) layers that make up the graded part of the intrinsic layer near the interfaces of a-SiGe:H solar cells. Therefore the graded part is approached with a ‘staircase’ bandgap profile, consisting of three layers within which the material properties are constant. Calibrated model parameters are obtained by matching simulation results of material properties of intrinsic a-SiGe:H single layers to measurements. Using the obtained model parameter sets subsequent simulations of p-i-n devices with intrinsic material similar to the single layers are matched to measured current-voltage characteristics. The changes in parameter values are evaluated as a function of optical gap.

scholarly journals Systematic derivation of a surface polarisation model for planar perovskite solar cells

2018 ◽  
Vol 30 (3) ◽  
pp. 427-457 ◽  
Author(s):  
N. E. COURTIER ◽  
J. M. FOSTER ◽  
S. E. J. O'KANE ◽  
A. B. WALKER ◽  
G. RICHARDSON
Keyword(s):  
Solar Cells ◽  
Numerical Solutions ◽  
Perovskite Solar Cells ◽  
Practical Interest ◽  
Operating Conditions ◽  
Asymptotic Approach ◽  
Perovskite Layer ◽  
Current Voltage ◽  
Wide Range ◽  
Vacancy Density

Increasing evidence suggests that the presence of mobile ions in perovskite solar cells (PSCs) can cause a current–voltage curve hysteresis. Steady state and transient current–voltage characteristics of a planar metal halide CH3NH3PbI3PSC are analysed with a drift-diffusion model that accounts for both charge transport and ion vacancy motion. The high ion vacancy density within the perovskite layer gives rise to narrow Debye layers (typical width ~2 nm), adjacent to the interfaces with the transport layers, over which large drops in the electric potential occur and in which significant charge is stored. Large disparities between (I) the width of the Debye layers and that of the perovskite layer (~600 nm) and (II) the ion vacancy density and the charge carrier densities motivate an asymptotic approach to solving the model, while the stiffness of the equations renders standard solution methods unreliable. We derive a simplifiedsurface polarisationmodel in which the slow ion dynamics are replaced by interfacial (non-linear) capacitances at the perovskite interfaces. Favourable comparison is made between the results of the asymptotic approach and numerical solutions for a realistic cell over a wide range of operating conditions of practical interest.

scholarly journals Особенности транспорта электронов и фотопроводимости в слое наноразмерных частиц сульфида свинца

2019 ◽  
Vol 45 (8) ◽  
pp. 3
Author(s):  
М.И. Шишкин ◽  
М.В. Гавриков ◽  
И.Т. Ягудин ◽  
А.Г. Роках
Keyword(s):  
Basic Mechanism ◽  
Charge Carriers ◽  
Optical Measurements ◽  
Free Charge ◽  
Current Voltage ◽  
Wide Range ◽  
Current Change ◽  
Current Voltage Characteristics ◽  
Lead Sulfide Nanoparticles ◽  
A Current

In the lead sulfide nanoparticles-based layers deposited from alcohol suspensions, analysis of the current-voltage characteristics made it possible to establish the basic mechanism of electron transport. Previously, using optical measurements in the range of 3500 nm, it was shown that the organic component in such layers was practically absent. When exposed to wide range radiation corresponding to the “transparency window” of the atmosphere of 8000–14000 nm, a current change in PbS nanodust was detected, where, as previously shown, absorption on free charge carriers can occur.

scholarly journals Hybrid quasi-3D optimization of grid architecture for single junction photovoltaic converters

2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Veikka Nikander ◽  
Jianguo Wei ◽  
Arto Aho ◽  
Ville Polojarvi ◽  
Antti Tukiainen ◽  
...  
Keyword(s):  
3D Model ◽  
Numerical Study ◽  
Operating Conditions ◽  
Grid Spacing ◽  
Loss Mechanism ◽  
Nonuniform Illumination ◽  
Current Voltage ◽  
Different Temperatures ◽  
Optimal Spacing ◽  
Current Voltage Characteristics

AbstractA numerical study of metal front contacts grid spacing for photovoltaic (PV) converter of relatively small area is presented. The model is constructed based on Solcore, an open-source Python-based library. A three-step-process is developed to create a hybrid quasi-3D model. The grid spacing under various operating conditions was assessed for two similar p–n and n–p structures. The key target was finding optimal configuration to achieve the highest conversion efficiency at different temperatures and illumination profiles. The results show that the n–p structure yields wider optimal spacing range and the highest output power. Also, it was found that temperature increase and illumination nonuniformity results in narrower optimal spacing for both structure architectures. Analyzing the current–voltage characteristics, reveals that resistive losses are the dominant loss mechanism bringing restriction in terms of ability to handle nonuniform illumination.

Experimental Performance Evaluation of a High Temperature PEM Fuel Cell Prototype Under Various Operating Conditions

2011 ◽  
Author(s):  
Susanta K. Das
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Operating Temperature ◽  
Pem Fuel Cell ◽  
Operating Conditions ◽  
Co Poisoning ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Fuel Stream ◽  
High Temperature Pem

In this study, we experimentally evaluated our newly designed high temperature PEM fuel cell (HTPEMFC) prototype performance at different operating conditions. In particular, we investigated the effects of operating temperature, pressure, air stoichiometry and CO poisoning in the anode fuel stream on the current-voltage characteristics of the HTPEMFC prototype. Experimental results obtained from the single HTPEM fuel cell show that the performance is quite steady with high CO-level reformate at high operating temperature which makes it possible to feed the reformate gas directly from the reformer to the stack without further CO removal. In order to develop design parameters for fuel reformer, experimental data of this type would be very useful. The results obtained from this study showed significant variations in current-voltage characteristics of HTPEMFC at different temperatures with different CO poisoning rates. The results are promising to understand the overall system performance development strategy of HTPEMFC in terms of current-voltage characteristics while fed with reformate with different CO ratios in the anode fuel stream.

Experimental Evaluation of CO Poisoning of a 5-Cell Stack High Temperature PEM Fuel Cell Prototype

2009 ◽  
Author(s):  
Susanta K. Das ◽  
Antonio Reis ◽  
K. Joel Berry
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
System Performance ◽  
Pem Fuel Cell ◽  
Operating Conditions ◽  
Co Poisoning ◽  
Fuel Cell Stack ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
High Temperature Pem

In this study, we experimentally studied our newly designed and built 5-cell stack high temperature PEM fuel cell prototype at different operating conditions to investigate the effects of CO poisoning on the cell performance. The effects of temperature variations with different amount of CO poisoning on the current-voltage characteristics of the fuel cell stack are investigated. Experimental data of this type would be very useful to develop design parameters for fuel reformer. The high CO tolerance of high temperature PEM fuel cell stack makes it possible to feed the reformate gas directly from the reformer without further CO removal. Thus, upon considering the fact that a steam reformer is a consumer of heat and water, and the fuel cell stacks are a producer of heat and water, the integration of the fuel cell stack and the reformer is expected to improve the entire system performance. The results obtained from our 5-cell stack test showed variations in current-voltage characteristics at different temperatures with different CO poisoning rates. The results are promising to understand the overall system performance development strategy of high temperature PEM fuel cell in terms of current-voltage characteristics while fed with on-site reformate hydrogen gas with different CO concentrations in the anode feed stream.

scholarly journals Temperature dependent analytical model for submicron GaAs-MESFET

2021 ◽  
Vol 10 (3) ◽  
pp. 1271-1282
Author(s):  
Mohamed Djouder ◽  
Arezki Benfdila ◽  
Ahcene Lakhlef
Keyword(s):  
Analytical Model ◽  
Temperature Dependent ◽  
Gaas Mesfet ◽  
Voltage Variation ◽  
Proposed Model ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Simulation Results ◽  
Parameter Values ◽  
Good Agreement

MESFET are used in circuitsof gigahertz frequencies as they are based on gallium arsenide (GaAs) having electron mobility six times higher than that of silicon. An analytical model simulating different device current-voltage characteristics, i.e., output conductance and output transconductance of a 0.3μm gate MESFET with temperature dependence is proposed. The model is validated by comparing the results of the proposed model and those of the numerical simulation. The parameter values are computed using an intrinsic MESFET of two-dimensional geometry. In this work, the distribution of different output loads for varied applied voltages is considered. Simulation results obtainedunder temperature variation effectsfor load distribution and applied driven voltage variation are considered. The RMS and average errors between the different models and GaAs MESFET simulations are calculated to evidence the proposed model accuracy. This was demonstrated by a good agreement between the proposed model and the simulation results, which are found in good agreement. The simulation results obtained under temperature variations were discussed and found to complement those obtained in the literature. This clarifies the relevance of the suggested model analytical.

Multi-Level Trap Assisted Tunneling Model for the Field and Temperature Dependence of SiC-JBS Reverse Leakage Current

2018 ◽  
Vol 924 ◽  
pp. 601-604 ◽  
Author(s):  
Gary Dolny ◽  
Yang Sheng ◽  
Yue Fu ◽  
S. Li ◽  
Rahul Radhakrishnan ◽  
...  
Keyword(s):  
Leakage Current ◽  
Thermionic Emission ◽  
Tunneling Model ◽  
Reverse Leakage Current ◽  
Current Voltage ◽  
Wide Range ◽  
Trap Assisted Tunneling ◽  
Current Voltage Characteristics ◽  
Multi Level ◽  
Assisted Tunneling

The reverse-bias current-voltage characteristics of commercial 1200 V 4H-silicon-carbide junction barrier Schottky (SiC-JBS) rectifiers are studied both experimentally and through numerical simulation. The reverse leakage current measured from physical devices is observed to display both a strong temperature and field dependence. A model is presented to explain the observed behavior based on a combination of trap-assisted tunneling and a thermionic-emission mechanism through a potential barrier located at the metal-SiC interface. The study shows that a two-level trapping model can be necessary to properly explain the measured data. Excellent agreement between the models and the measurements is obtained over a wide range of bias and temperature.

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