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The results of investigation of discharge characteristics of the Penning plasma source are presented. Volt-ampere characteristics (VAC), energy distribution, and mass-charge composition of ions emitted from the discharge under different modes of its combustion were measured. The connection between the discharge current bursts and increase in the potential drop (up to 50% of the anode voltage) is established. The measured VACs agree well with the theoretical dependencies. It is shown that the content of atomic hydrogen ions increases from 5 to 10% with an increase in the anode voltage from 1 to 3.5 kV and the power applied in the discharge (from 0.2 to 3 W). [ABSTRACT FROM AUTHOR]

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Presently we explored quantum confinement (QC) in three-nanolayer sandwich systems, composed of Au-SnO 2 -Fe, Au-SnO 2 -Si and Au-SnO 2 -Ag layers. We recorded the absorption spectra of these sandwich systems, all with discrete structure. We recorded the action spectra of the photocurrent for the Au-SnO 2 -Fe sandwich system, with the photocurrent quantum yields increasing with the photon energy, achieving 3.1 at 4.7 × 10 4 cm −1 . The photocurrent action spectra correlate with high accuracy with optical absorption spectra. We discuss the mechanisms determining the absorption bandwidth value, including surface imperfections, thermal distribution of the vibrational level populations in the electronic ground state, and the diabatic coupling of levels of the excited state to those of a “dark” state. Volt-Ampere (V/A) characteristics were recorded for all three of the sandwich systems, quite similar to those of a Schottky diode. We report the parameter values of the V/A characteristics, found by fitting the experimental data with a theoretical curve. We also report charge density changes in the SnO 2 layer caused by low constant voltage applied to the sandwich structure, observed as changes in the absorption band intensity. [ABSTRACT FROM AUTHOR]

This paper mainly studied charging and electric field characteristics of different proportions of biomass/coal co-combustion ashes (co-ash) in a self-designed high-voltage electrostatic field, including an evaluation of charging, volt-ampere and plate current density distribution characteristics of co-ash. In addition, the mechanisms that influenced charging and electric field characteristics were discussed by analyzing the morphology, chemical composition and specific resistance of co-ash. The research results showed that with an increase of biomass ratio in the co-combustion fuel, the charge-mass ratio of co-ash displayed a rising trend to a certain extent, and gradually enhanced particle-charging characteristics. The co-ash in an electric field manifested a property of being easier to charge, so a more optimal volt-ampere characteristic was obtained. Simultaneously, the results also indicated that the plate current density distribution of co-ash showed limited change with an increase of biomass ratio in co-combustion. [ABSTRACT FROM AUTHOR]

Dynamic VAR compensation (DVC) is gaining increasing attentions with growing construction of high-voltage DC systems and renewable power plants in modern power system. This study proposes a novel zoning-based heuristic planning method to reduce the sites and capacity of DVC installation. Clustering algorithm based on buses' dynamic behaviour correlation and voltage control ability is developed to partition the system into several control zones. Then, candidate DVC sites are determined by zones, which narrow the searching space and avoid excessive installation of DVCs on adjacent buses. The voltage control index is proposed to find proper DVC installation locations by zones and capacity optimisation is then carried out to reduce investment. The proposed methodology is demonstrated on a modified New England 39-bus test system with wind farm integration. Performance comparison with conventional planning scheme confirms the advantages of the new heuristic planning scheme in practical applications. [ABSTRACT FROM AUTHOR]

The magnetization component of input current of low-rating three-phase induction motor is large which results in poor power factor particularly at low-load conditions. The situation becomes critical when motor is fed from a distributed generating (DG) system. In this paper, the performance analysis of induction motor is carried out for minimum input VA. A distinct novel slip is found at which the input VA is minimum independent of the load conditions. This optimum slip is expressed in terms of motor per-phase equivalent circuit parameters. This novel relationship is valid for every induction motor. As compared to rated conditions, a drastic reduction in VA with a large improvement in power factor is observed. Although, a marginal change in output power and efficiency is recorded. All the analytical, simulated and experimental results match each other with a very fair degree of accuracy. [ABSTRACT FROM AUTHOR]

Proposed methods of modeling of electrical and temperature characteristics of single-electron transistor for providing information to system of computer-aided design Electronics Workbench. Analyzed dependence in current-voltage characteristics of nano-device trough values of temperature and operating mode. [ABSTRACT FROM AUTHOR]

Proposed nonlinear defect concentration model of metal-semiconductor contact. It is shown that taking into account nonlinear dependence of the Fermi energy EF defect concentration leads to higher barrier Schottky in 15-25 %. Calculated Volt-Amper characteristics of the diodes are consistent with experiment. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the impact of different Electric Vehicle (EV) penetration on quasi real-time Volt–VAR Optimization (VVO) of smart distribution networks. Recent VVO solutions enable capturing data from Advanced Metering Infrastructure (AMI) in quasi real-time to minimize distribution networks loss costs and perform Conservation Voltage Reduction (CVR) to save energy. The emergence of EVs throughout distribution feeder increases grid complexity and uncertainty levels that could affect AMI-based VVO objectives. Hence, this paper primarily introduces an AMI-based VVO engine, able to minimize grid loss and Volt–VAR control assets operating costs while maximizing CVR benefit. It then presents a real-time co-simulation platform comprised of the VVO engine, grid model in a real-time simulator and monitoring platform, communicating with each other through DNP.3 protocol, to test the precision and performance of AMI-based VVO in presence of different EV penetration levels. Accordingly, 33-node distribution feeder is studied through different EV penetration scenarios. The results show significant changes in AMI-based VVO performance especially in CVR sub-part of VVO according to EV model and type. Thus, this study could lead near future VVO solutions to gain higher levels of accuracy and efficiency considering smart microgrid components such as EV in their models. [ABSTRACT FROM AUTHOR]

This paper considers the major factors affecting the nonlinearity in the volt-ampere characteristics of resistive gas sensors. The authors establish that, under small gaps between sensor electrodes (particularly, in multisensor systems), the dominating contribution to the nonlinearity is made by three factors, namely, the drift of chemisorbed ions to an anode, the drift of protons on the surface to a cathode and the drift of intrinsic defects through the sublattice. [ABSTRACT FROM AUTHOR]

The discharge phenomena for micro meter gap sizes include many interesting problems from engineering and physical perspectives. In this paper, the authors deal with the experimental and theoretical results of the breakdown voltage and current-voltage characteristics of the direct-current helium and hydrogen discharges. The measurements were performed at a constant pressure of around one atmosphere, while varying the gap size between two parallel plane tungsten electrodes between 1 μm and 100 μm. From the measured breakdown voltage curves, the effective yields and the ionization coefficients were derived for both gases. Present data for the ionization coefficients correlate with the data obtained for the breakdown voltage curves measured for fixed 100 μm interelectrode separation. The current-voltage characteristics were plotted for the various gap sizes illustrating the role of the field emission effects in the microgaps. Based on the Fowler-Nordheim theory, the enhancement factors were determined. The gap spacing dependence of the field emission current can be explained by the introduction of two ideas, the first being a space charge effect by emitted electrons, and the second a change in the breakdown mechanism. Experimental results, presented here, demonstrate that Townsend phenomenology breaks down when field emission becomes the key mechanism affecting the breakdown and deforming the left hand side of the breakdown voltage curves. [ABSTRACT FROM AUTHOR]

Two methods of determining the arc currents in three-phase single-chamber alternating-current generators are presented. In the first method, the current traversing one of the electrode spacings in a three-phase network is disregarded. The second method is based on the consideration of the general mechanisms of the gas flows around arcs. In this method, the volt-ampere characteristic of an arc discharge is constructed from the calculated values of the voltage drop across the arc that are closest to the measured values of this drop. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new voltage and VAR control method is developed. [•] Distributed generation is utilized for optimizing voltage and VAR control. [•] Mixed integer non-linear programming is used to model the problem. [ABSTRACT FROM AUTHOR]

Results are presented for an experimental study of the influence exerted on the effectiveness of an electrostatic cyclone by the initial concentration and inlet velocity of a dust aerosol with a high electrical resistance. The volt-ampere characteristics of the unit are also presented. Recommendations are given for optimal operating regimes. [ABSTRACT FROM AUTHOR]

A combined threshold position-sensitive photoswitch with an S-shaped volt-ampere characteristic is proposed. It is shown that the voltage switch-on of this element depends on the spatial position of the light beam on its surface. The results of the mathematical simulation and experimental studies of this device are given. [ABSTRACT FROM AUTHOR]

Owing to the shortcomings of existing series arc fault detection methods, based on a summary of arc volt–ampere characteristics, the change rule of the line current and the relationship between the voltage and current are deeply analyzed and theoretically explained under different loads when series arc faults occur. A series arc fault detection method is proposed, and the software flowchart and principles of the applied hardware implementation are given. Finally, a prototype of an arc fault detection device (AFDD) with a rated voltage of 220 V and a rated current of 40 A is developed. The prototype was tested according to experimental methods provided by the Chinese national standard, GB/T 31143-2014. The experimental results show that the proposed detection method is simple and practical, and can be implemented using a low-cost microprocessor. The proposed method will provide good theoretical guidance in promoting the research and development of an AFDD. [ABSTRACT FROM AUTHOR]

In this paper we demonstrate and analyse the influence of cathode surface inhomogeneities on the breakdown, volt–ampere (V–A) characteristics and the spatial structure of the low-pressure non-equilibrium discharges. The idea for this work came from the need to explain the non-typical V–A characteristics (positive slope of the characteristics in low-current regime of the discharge) that we observed in a parallel-plate, dc discharge in nitrogen. It was found that the cathode was locally conditioned by the discharge that operated in the constricted glow regime. Spatial inhomogeneity of the cathode surface strongly affected the subsequent operation in the breakdown-Townsend regime where discharge is supposed to be uniform. [ABSTRACT FROM AUTHOR]