Many-particle based evaluations for maximum current output from bimodal electron emitter arrays

2021 ◽  
Vol 129 (17) ◽  
pp. 173301
Author(s):  
D. Guo ◽  
W. Milestone ◽  
R. P. Joshi
Keyword(s):  
Current Output ◽  
Electron Emitter ◽  
Maximum Current

scholarly journals Dynamic Voltage Support of Converters during Grid Faults in Accordance with National Grid Code Requirements

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2484 ◽  
Author(s):  
Jürgen Marchgraber ◽  
Wolfgang Gawlik
Keyword(s):  
Simulation Model ◽  
System Stability ◽  
Current Output ◽  
Current Limitation ◽  
Fault Ride Through ◽  
Maximum Current ◽  
Dynamic Voltage ◽  
Grid Codes ◽  
Voltage Support ◽  
A Current

To ensure system stability, national grid codes often require converter-based generators to provide fault-ride-through (FRT) capabilities and dynamic voltage support, according to which they should stay connected and support the voltage during fault situations. The requirements for dynamic voltage support include the injection of reactive current in the positive- as well as negative-sequence system, directly proportional to the change of the corresponding voltage between fault and pre-fault. Since this requirement may lead to a reference current surpassing the maximum current capability, the converter control has to contain a proper current limitation. This paper presents an algorithm for such a current limitation and a simulation model of a converter and its control, which applies this algorithm. Based on voltage measurements, which were measured during forced short-circuits in the real grid, the simulation model is used to simulate the behavior of a converter in reaction to these voltage measurements. The results show that the converter control using this algorithm for current limitation guarantees a current output below the maximum current capability while respecting the requirements for dynamic voltage support of the relevant grid codes.

scholarly journals Wind driven semiconductor electricity generator with high direct current output based on a dynamic Schottky junction

RSC Advances ◽  
2021 ◽  
Vol 11 (31) ◽  
pp. 19106-19112
Author(s):  
Xutao Yu ◽  
Haonan Zheng ◽  
Yanghua Lu ◽  
Runjiang Shen ◽  
Yanfei Yan ◽  
...  
Keyword(s):  
Wind Energy ◽  
Direct Current ◽  
Schottky Junction ◽  
Current Output

In this study, a generator based on a metal/semiconductor dynamic Schottky junction has achieved ultrahigh and continuous direct current output by harvesting wind energy.

scholarly journals Transient Current Density in a Pair of Long Parallel Conductors

2021 ◽  
Vol 11 (15) ◽  
pp. 6920
Author(s):  
Oldřich Coufal
Keyword(s):  
Steady State ◽  
Cross Section ◽  
Current Density ◽  
Circular Cross Section ◽  
Transient Current ◽  
Constant Current ◽  
Voltage Source ◽  
Sinusoidal Voltage ◽  
Steady State Current ◽  
Maximum Current

Two infinitely long parallel conductors of arbitrary cross section connected to a voltage source form a loop. If the source voltage depends on time, then due to induction there is no constant current density in the loop conductors. It is only recently that a method has been published for accurately calculating current density in a group of long parallel conductors. The method has thus far been applied to the calculation of steady-state current density in a loop connected to a sinusoidal voltage source. In the present article, the method is used for an accurate calculation of transient current using transient current density. The transient current is analysed when connecting and short-circuiting the sources of sinusoidal, constant and sawtooth voltages. For circular cross section conductors, the dependences of maximum current density, maximum current and the time of achieving steady state on the source frequency, the distance of the conductors and their resistivity when connecting the source of sinusoidal voltage are examined.

scholarly journals Stabilization of Li0.33La0.55TiO3 Solid Electrolyte Interphase Layer and Enhancement of Cycling Performance of LiNi0.5Co0.3Mn0.2O2 Battery Cathode with Buffer Layer

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 989
Author(s):  
Feihu Tan ◽  
Hua An ◽  
Ning Li ◽  
Jun Du ◽  
Zhengchun Peng
Keyword(s):  
Solid State ◽  
Ionic Conductivity ◽  
Solid Electrolyte ◽  
Buffer Layer ◽  
Solid Electrolyte Interphase ◽  
Cycling Performance ◽  
Physical Contact ◽  
Initial State ◽  
Amorphous Sio2 ◽  
Current Output

All-solid-state batteries (ASSBs) are attractive for energy storage, mainly because introducing solid-state electrolytes significantly improves the battery performance in terms of safety, energy density, process compatibility, etc., compared with liquid electrolytes. However, the ionic conductivity of the solid-state electrolyte and the interface between the electrolyte and the electrode are two key factors that limit the performance of ASSBs. In this work, we investigated the structure of a Li0.33La0.55TiO3 (LLTO) thin-film solid electrolyte and the influence of different interfaces between LLTO electrolytes and electrodes on battery performance. The maximum ionic conductivity of the LLTO was 7.78 × 10−5 S/cm. Introducing a buffer layer could drastically improve the battery charging and discharging performance and cycle stability. Amorphous SiO2 allowed good physical contact with the electrode and the electrolyte, reduced the interface resistance, and improved the rate characteristics of the battery. The battery with the optimized interface could achieve 30C current output, and its capacity was 27.7% of the initial state after 1000 cycles. We achieved excellent performance and high stability by applying the dense amorphous SiO2 buffer layer, which indicates a promising strategy for the development of ASSBs.

scholarly journals A Graphical Design Methodology Based on Ideal Gyrator and Transformer for Compensation Topology with Load-Independent Output in Inductive Power Transfer System

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 575
Author(s):  
Qian Su ◽  
Xin Liu ◽  
Yan Li ◽  
Xiaosong Wang ◽  
Zhiqiang Wang ◽  
...  
Keyword(s):  
Phase Angle ◽  
Design Methodology ◽  
Constant Current ◽  
Current Gain ◽  
Transfer System ◽  
Power Transfer ◽  
Current Output ◽  
Inductive Power Transfer ◽  
Zero Phase ◽  
Inductive Power

Compensation is crucial in the inductive power transfer system to achieve load-independent constant voltage or constant current output, near-zero reactive power, higher design freedom, and zero-voltage switching of the driver circuit. This article proposes a simple, comprehensive, and innovative graphic design methodology for compensation topology to realize load-independent output at zero-phase-angle frequencies. Four types of graphical models of the loosely coupled transformer that utilize the ideal transformer and gyrator are presented. The combination of four types of models with the source-side/load-side conversion model can realize the load-independent output from the source to load. Instead of previous design methods of solving the equations derived from the circuits, the load-independent frequency, zero-phase angle (ZPA) conditions, and source-to-load voltage/current gain of the compensation topology can be intuitively obtained using the circuit model given in this paper. In addition, not limited to only research of the existing compensation topology, based on the design methodology in this paper, 12 novel compensation topologies that are free from the constraints of transformer parameters and independent of load variations are stated and verified by simulations. In addition, a novel prototype of primary-series inductor–capacitance–capacitance (S/LCC) topology is constructed to demonstrate the proposed design approach. The simulation and experimental results are consistent with the theory, indicating the correctness of the design method.

scholarly journals Simple Synthesis of Red Iridium(III) Complexes with Sulfur-Contained Four-Membered Ancillary Ligands for OLEDs

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2599
Author(s):  
Meng-Xi Mao ◽  
Fang-Ling Li ◽  
Yan Shen ◽  
Qi-Ming Liu ◽  
Shuai Xing ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Quantum Yields ◽  
Rapid Preparation ◽  
Maximum Brightness ◽  
Ancillary Ligands ◽  
Light Emitting ◽  
Maximum Current ◽  
Electron Donating Groups ◽  
Sulfur Containing ◽  
Main Ligand

Phosphorescent iridium(III) complexes have been widely researched for the fabrication of efficient organic light-emitting diodes (OLEDs). In this work, three red Ir(III) complexes named Ir-1, Ir-2, and Ir-3, with Ir-S-C-S four-membered framework rings, were synthesized efficiently at room temperature within 5 min using sulfur-containing ancillary ligands with electron-donating groups of 9,10-dihydro-9,9-dimethylacridine, phenoxazine, and phenothiazine, respectively. Due to the same main ligand of 4-(4-(trifluoromethyl)phenyl)quinazoline, all Ir(III) complexes showed similar photoluminescence emissions at 622, 619, and 622 nm with phosphorescence quantum yields of 35.4%, 50.4%, and 52.8%, respectively. OLEDs employing these complexes as emitters with the structure of ITO (indium tin oxide)/HAT-CN (dipyra-zino[2,3-f,2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile, 5 nm)/TAPC (4,4′-cyclohexylidenebis[N,N-bis-(4-methylphenyl)aniline], 40 nm)/TCTA (4,4″,4″-tris(carbazol-9-yl)triphenylamine, 10 nm)/Ir(III) complex (10 wt%): 2,6DCzPPy (2,6-bis-(3-(carbazol-9-yl)phenyl)pyridine, 10 nm)/TmPyPB (1,3,5-tri(mpyrid-3-yl-phenyl)benzene, 50 nm)/LiF (1 nm)/Al (100 nm) achieved good performance. In particular, the device based on complex Ir-3 with the phenothiazine unit showed the best performance with a maximum brightness of 22,480 cd m−2, a maximum current efficiency of 23.71 cd A−1, and a maximum external quantum efficiency of 18.1%. The research results suggest the Ir(III) complexes with a four-membered ring Ir-S-C-S backbone provide ideas for the rapid preparation of Ir(III) complexes for OLEDs.

Large‐area lanthanum hexaboride electron emitter

1985 ◽  
Vol 56 (9) ◽  
pp. 1717-1722 ◽  
Author(s):  
D. M. Goebel ◽  
Y. Hirooka ◽  
T. A. Sketchley
Keyword(s):  
Lanthanum Hexaboride ◽  
Large Area ◽  
Electron Emitter
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