Direct Current Voltage Source Research Articles

N-type semiconductor with energy storage made from chitosan

Chitosan, obtained from crustaceans such as crabs and shrimp, has been mainly used in medicine; however, no studies on its use in electronic applications with semiconducting and large storage properties have been reported. Here, we report an n-type semiconducting biomaterial with energy storage properties of 694.4 mJ/m2 consisting of a chitosan nanofiber (ChNF) film with N-type negative resistance. The ChNF generates an alternative-current wave with a frequency of 7.8 MHz at a threshold voltage of 187 MV/m from a direct-current voltage source, with the switching effect of a third-order resistance change. This is due to the Gunn effect, caused by the repeated voltage-induced generation of a strong electric field domain (electric double layer) at the cathode and its disappearance at the anode of the ChNF device. Electron spin resonance spectral analysis showed that conducting electrons of the ChNF were identified as radicals on the aminyl radical, N·H. Paper electronics made from marine products are a great boon to a renewable society.

DC-driven subatmospheric glow discharges in the infrared-stimulated

This paper presents a conceptual framework for experimental research combined with numerical analysis on direct current (DC) glow discharges in microscale planar gas discharge-semiconductor systems (GDSS). In the experimental section, several structural and elemental analyses, including SEM, EDAX, AFM, and near-infrared absorption spectra measurements were carried out for compound semiconductor zinc selenide (ZnSe) cathode sample. Argon (Ar) was charged into the plasma reactor cell of GDSS at pressures of 100 Torr subatmospheric and 760 Torr atmospheric, respectively, by a vacuum pump- gas filling station. Glow discharge light emissions from plasma, excited under three different intensity levels (dark, weak, strong) of infrared beam illumination on ZnSe cathode electrode, were measured by using a phomultiplier tube that is sensitive to UV–Visible wavelengths. In the numerical analysis section, simulation studies were carried out on the two-dimensional gas discharge-semiconductor microplasma system (GDSµPS) cell models using the finite-element method (FEM) solver COMSOL Multiphysics DC plasma program. Calculations and predictions were based on mixture-averaged diffusion drift theory and Maxwellian electron energy distribution function. GDSµPS cell was modeled in a square chamber with planar anode/cathode electrode pair coupled at a 50 μm discharge gap. Single side of ZnSe cathode was finely micro-digitated to increase the effective surface area for enhanced electron emission to the gas discharge cell. The electrical equivalent circuit (EEC) of the proposed model was driven by 1.0 kV DC voltage source. Binary Ar/H2 gas medium in a mixture of 3:2 molar ratio was introduced to the gas discharge chamber at constant 200 Torr subatmospheric pressure. Simulations were run for normal glow discharges to exhibit the electrical fast transient glow discharge behaviours from electron field emission state to self-sustained normal glow discharge state by numerically solving the electron density (ED), electron current density (ECD) and electric potential distribution (EPD) parameters.It is figured out that binary Ar/H2 gas discharge model can undertake a major role in shaping and controlling the spatiotemporal response to transient electro-optical behavior of microplasma-based artificial electromagnetic materials configured for high-efficiency infrared-to-visible wavelength conversion applications.

A single‐source switched‐capacitor‐based 25‐level sextuple boost inverter with a low switch count

AbstractToday, multilevel inverters are widely utilized in various applications. Reducing the number of components in the design of these converters is one of the crucial goals so that they have less volume and cost. This paper presents a single‐source structure for a multilevel switched‐capacitor inverter with voltage boost capability. The proposed structure can generate 25 sinusoidal‐like step voltage levels with a six times amplitude increase compared to the input. This converter uses only one direct current (DC) power source, 14 switches, and four capacitors. The nearest level control switching method has been used to control the converter, create voltage levels, and select the switching modes. A comprehensive comparison has been made with other recently presented structures to demonstrate the efficiency of the proposed structure. The advantages of the proposed structure include using only one DC voltage source, the ability to increase the output voltage six times compared to the input, the use of fewer power electronics components compared to the number of voltage levels, proper efficiency, self‐balancing of capacitors, and as a result, the lower cost. The performance accuracy of the proposed converter has been simulated in the MATLAB Simulink environment and then evaluated by a laboratory prototype.

Comprehensive Analysis and Experiment of Extreme Faults in MMC Based on IGCT

High voltage direct current voltage source converter (HVDC-VSC) technology is one of most important solutions for transmission of large-scale renewable sources. Modular multilevel converter (MMC) is one of the most popular topologies for HVDC-VSC system. The extreme faults affect the safety and reliability of MMC greatly. This paper gives comprehensive analysis and experiment of extreme faults in MMC based on integrated gate commutated thyristor (IGCT). Causes and characterization of the extreme faults are analyzed in detail. A new protection solution based on IGCT with controlled punch-through design (CP-IGCT) and fast recovery diode with high surge current capability (HS-FRD) is proposed. The surge current capability of HS-FRD is validated via experiment successfully. Theoretical calculation shows that the protection solution based on CP-IGCT and HS-FRD can help reduce the maximum fault current below 50% when the anode inductor is 0.8 μH in the extreme shoot-through fault. Test results show that the protection solution can realize the discharge of the DC capacitor below 4.5 kV in the extreme shoot-through fault. The maximum fault current in MMC based on IGCT is only about 600 kA while the maximum fault current in MMC based on insulated gate bipolar transistor (IGBT) is over 1100 kA. Explosion proof of CP-IGCT is validated during the tests, which is similar to that of the protection thyristor. However, IGBT can't guarantee the stability of the package and may cause severe safety problem. The failed CP-IGCT has the short circuit failure mode (SCFM) and can be used for bypass of the faulty MMC sub-module (MMC-SM). Via comparison, the proposed protection solution has lowest cost and complexity, as well as the highest safety.

A novel n-type semiconducting biomaterial

There has been no research conducted thus far on the semiconducting behaviour of biomaterials. In this study, we present an n-type semiconducting biomaterial composed of amorphous kenaf cellulose fibre (AKCF) paper with a voltage-controlled N-type negative resistance. The AKCF generates an alternating-current wave with a frequency of 40.6 MHz from a direct-current voltage source at its threshold voltage (electric field of 5.26 kV/m), which is accompanied by a switching effect with a four-order resistance change at 293 K. This effect is attributed to the voltage-induced occurrence of strong field domains (electric double layers) at the cathode and depletion at the anode of the AKCF device. The proposed AKCF material presents considerable potential for applications in flexible/paper electronic devices such as high frequency power sources and switching effect devices.

Pengukuran Nilai Selisih Error Tegangan Keluaran Catu Daya DC dengan Menggunakan Multimeter Digital dan Multimeter Analog pada Praktikum Laboratorium Dasar Elektronika dan Rangkaian Listrik Jurusan Teknik Elektro Universitas Sriwijaya

The power supply as a voltage source with a DC (Direct Current) output voltage or direct current is often used for electronic equipment, both office equipment and household equipment (Imam Saukani, 2020). In using the power supply, the output voltage is selected and high accuracy is required to obtain the output voltage that suits the user's needs. Often times, the power supply used in the practicum does not produce the right output voltage. The purpose of this study is to determine the value of the difference in the output voltage error generated after first determining the voltage value to be used at no-load using a digital multimeter and an analog multimeter as a comparison. After measuring the output voltage of the power supply, the correct voltage value is obtained in each practicum, measurements made at the same time can give definite results of the value of the output voltage of the power supply, the relatively small difference in results ensures that the power supply is in good condition, the output voltage of the power supply is measured using the measuring instrument with repeated measurements 7 (seven) times at each predetermined voltage and obtained a difference of 0.01V – 0.02V. After taking measurements using digital and analog multimeters, it can be concluded that measurements made before the practicum by measuring the output voltage of the power supply can help get the correct voltage value in each practicum, measurements by comparing measuring instruments at the same time can provide definite results of the resulting voltage value by the power supply, the difference in the results obtained is relatively small so as to ensure that the power supply is in good condition, the power supply can be used on loads or electronic equipment that requires a DC voltage source (Genta Subni Ananda Putra, et al, 2020). Practicum can be done well by measuring the output voltage of the power supply. This difference in output voltage results is what the author uses as research material for scientific writing which aims to find solutions to existing errors.

Practical implementation of 15 level inverter for THD reduction

Proposed designed of inverter incorporates three stage Topology with 15 levels resulting compact power control device. During this paper authors had made an attempt to propose a framework utilizing simply ten changes to provide fifteen levels for obtaining less mutilated and swish waveform, after declining costs and a diverse environment, implementing a few changes, encourages less exchange time and an improved Topology. After setting the stage and mixing at three Direct Current voltage sources (6Volts, 12Volts, and 24Volts), fifteen yield dimensions are achieved. The small leeway goal of put forth architecture is its comprehension to create yields voltage level without the H-circuit at the outlet converter. THDv% is 4% of the total test results satisfying (519) touchstones. Scheme put forth is useful for Voltage Restoring system, Voltage compensation system, Power Drives.

Light-controlled metasurface with a controllable range of reflection phase modulation

The reconfigurable metasurface (MS) with tunable electromagnetic scattering properties has had an impact on innovative communication applications. However, the widely studied MS controlled by direct-current (DC) bias requires complex physical control circuits in array wavefront encoding, while the light-controlled MS does not. In this paper, we report a new approach for a light-controlled MS with a controllable modulation range of reflection phase, and its unit is composed of a reflection phase element based on the varactor and an optical interrogation network (OIN) based on the photoresistor so that the phase distribution of each MS unit could be independently programmed optically. To illustrate our approach, a 2-bit reflection phase MS with 10 × 10 units was fabricated and tested to achieve pencil beam scanning and orbital angular momentum beam at microwave frequencies. The simulated and measured results verify the feasibility of the proposed design. Furthermore, all the OINs on the MS are connected in parallel and powered by the same DC voltage source, which simplifies the difficulty of array expansion in MS design with a large-scale array.

Low switching frequency modulation for generalized three-phase multilevel inverters geared toward Grid Codes compliance

In this paper, a generalized three-phase multilevel power inverter (MLI) structure is proposed under asymmetric configurations. The operating mode and the switching combinations are briefly exposed according to the parity of the number of direct current (DC) voltage sources in use. Subsequently, the proposed topology is evaluated in terms of commonly used factors and then benchmarked against some of the state-of the-art cascaded MLIs featuring multiple DC voltage sources (MDCS-CMLIs) while putting emphasis on the reduction of power switching devices. Moreover, a new nearest level control (NLC)-based modulation technique is designed for the purpose of better comply with some quality grid codes, namely the European EN 50160 and the International IEC 61000-2-12. The identification of the optimal control thresholds is realized by a constrained optimization algorithm (e.g., particle swarm optimization (PSO)) which is implemented in python script and validated through SIMULINK fast fourier transform (FFT) analysis tool. Lastly, the harmonic performance of the proposed technique is compared side-by-side with that of the conventional NLC scheme and exhibits significant reduction in harmonic distortion.

Extended hybrid cross-switched multilevel inverter circuit topology

PurposeMultilevel inverters (MLIs) have been studied widely over the past two decades because of their inherent advantages and interesting features. However, most of the newly introduced structures suffer from the increased standing voltage of the switches, which is defined as the maximum off-state voltage on the switches, losing modularity and increased number of direct current (DC) voltage sources. The purpose of this study is to propose a new hybrid MLI topology to alleviate the mentioned problems.Design/methodology/approachThe proposed approach in this study includes using the advantage of two different topologies and combine them in a way that the advantages of both of the topologies are achieved. Therefore, the approach is to design a hybrid topology from two existing topologies so that a new topology has resulted.FindingsThis paper proposes a new hybrid MLI with lower power electronic switches and lowers DC voltage sources in comparison with the classic structures. The proposed MLIs maintain a balance between the number of switches, the standing voltage on the switches and the number of DC sources. The topology description, modulation method and comparative study have been presented. Also, another more reduced structure is presented for higher power factor operation. The MATLAB simulation and experimental results of a nine-level inverter have been presented to verify its operation.Originality/valueThe hybrid topology has a new structure that has not been presented before. It is important to emphasize that the topology combination and achieving the hybrid topology is wisely accomplished to improve some features of the MLI.

Cascaded multilevel inverter based on ladder bridges: Analysis, optimization, and implementation

AbstractThis paper proposes a new ladder‐switch based cascaded multilevel inverter that requires a lower number of insulated gate bipolar transistors (IGBTs) and direct current (DC) voltage sources to generate a specified range of voltage levels. Regarding this topology, it consists of λ stages, where each stage comprises k legs, besides each leg composed of n cells. So, the proposed topology can be optimized to obtain the lower requirement for IGBTs and DC voltage sources. It is required to mention that this topology generates both negative and positive voltage levels inherently. Two different algorithms are presented to synthesize all odd and even voltage levels. After, regarding each of the algorithms, the proposed topology is optimized from different aspects of the lowest number of IGBTs or the lowest number of DC voltage sources, and results are depicted. A comparison assessment is performed to find the advantages and possible disadvantages of the proposed topology. In the end, a 23‐level prototype of the proposed topology is used to validate the correct performance of the proposed topology using the experimental results.

A generalized diode containing bidirectional topology for multilevel inverter with reduced switches and power loss

AbstractMultilevel inverters (MLIs) have made great strides in utilizing renewable energy and industrial applications compared to conventional two‐level inverters in terms of output voltage quality, smaller size of the output filter, and higher efficiency. This paper describes a new diode containing bidirectional topology for single‐phase MLI. This structure is presented to reduce the count of switches, isolated voltage sources, and drivers that can increase the number of output levels modularly. This converter, despite the use of diodes, can feed bidirectionally the low power factor inductive–resistive loads. The proposed structure has been designed to achieve a higher output voltage levels relative to the number of switches, drivers, and direct current (DC) voltage sources. Three different algorithms have been proposed to determine the values of DC voltage sources. To confirm the superiority of the proposed structure, a detailed comparison has been carried out with other MLI topologies. Then the proposed topology is simulated in Matlab/Simulink environment using the nearest level modulation technique. Finally, experimental results are presented to confirm the performance of the designed structure in symmetric and asymmetric topologies.

Static Reactive Power Compensator Design, Based on Three-Phase Voltage Converter

At present, electrical network stability is of the utmost importance because of the increase in electric demand and the integration of distributed generation deriving from renewable energy. In this paper, we proposed a static reactive power compensator model with common direct current voltage sources. Converter parameters were calculated and designed to fulfill specifications. In order to ascertain the device response for different operating modes as reactive power consumer and generator, we developed the model’s power and control circuits in Matlab Simulink. Simulations were performed for different conditions, and as a result, the current and voltage waveforms and the circular power chart were obtained. This paper has theoretically proven it is possible to achieve the consumption or generation of purely active or reactive power by implementing a static reactive power compensator with common DC voltage sources.

A Developed H-Bridge Cascaded Multilevel Inverter with Reduced Switch Count

Multilevel Inverter integrates several Direct Current (DC) sources to produce a single-phase Alternating Current (AC) waveform that can be used to meet the domestic and commercial power demand. This article introduces a novel Multi Source Cascaded Multilevel Inverter with a reduced number of switches for the efficient use of DC voltage sources. The conversion efficiency can be increased by the presented topology which is simple in design to overcome the significant switching losses in the power electronics devices. Optimal Firing Angle and Phase Opposition Disposition Pulse width Modulation Techniques were used to reduce the harmonics at the desired output of the inverter and also to improve the power quality of the presented topology. This article also proposes two Asymmetric Multilevel Inverter Topologies. A comparison has been made, on the number of switches required and the efficiency of the inverters to differentiate the presented Topologies from other topologies of the multilevel inverter. Finally, the performance characteristics of the presented topologies have been designed and investigated using MATLAB Simulation. Simulation results were validated using an experimental setup.

Scalable Electrochemical Synthesis of Novel Biogenic Silver Nanoparticles and Its Application to High-Sensitive Detection of 4-Nitrophenol in Aqueous System

This study reports a scalable green electrochemical synthesis of novel biogenic silver nanoparticles colloid (biogenic AgNPs) in large scale up to 5 liters using the bulk silver bar and the green tea leaves (Camellia sinensis) extract (GTE) as reducing agent during the electrochemical process. Under a direct-current voltage source, the biomolecules in GTE can release electrons to promote the reducing process of Ag+ to Ag0. More interestingly, the formation of the intermediate complex helps to cap on the nanoparticles, which leads to stabilizing AgNPs. The as-synthesized biogenic AgNPs with the size of 34 nm exhibit the outstanding electrochemical properties due to the presence of biomolecules on the biogenic AgNPs surface, which facilitates the effective attaching of AgNPs on the carbon surface of the screen-printed carbon electrode (SPE) through the formation of the strong C-O coordinate bonds between O atom of oxygen functional groups and C atom of SPE. The electrochemical properties of the biogenic AgNPs-modified SPE are enhanced significantly in comparison with bare SPE and pure AgNPs-SPE. The biogenic AgNPs-SPE is applied successfully to the detection of 4-nitrophenol (4-NP). The electrochemical sensor using biogenic AgNPs can reliably detect 4-NP in the linear range from 0.1 to 25 μM with the sensitivity about 6.69 μA μM-1 cm-2. The present work reveals, as the greener synthesis method with ultra-large scalable ability, high purity, and excellent electrochemical properties of biogenic AgNPs is very promising for technological applications in high-sensitive electrochemical chemosensors, nanopharmaceuticals, and other fields.

Design and implementation of an ecological cooler

This work shows the construction of an ecological cooler capable of fulfilling the functions of a conventional refrigerator, its operation is based on using Peltier cells which create cold on one side and heat on the other. It is about eliminating the use of refrigerant gases, which damage the ozone layer, in addition to oils and accessories that are harmful to the environment, electrical energy is also saved with the prototype. The construction of the prototype is based on the construction of a panel that has 2 Peltier cells, 3 fans and a radiator system, which is integrated into a cooling drawer, the system is connected to a direct current voltage source. The prototype is designed to be used as a cooling system to contain food mainly, in addition to completely eliminating the refrigerants and mechanical components that are used in conventional refrigeration, which cause contamination of the ozone layer and the environment.

Improving the Transient Stability of the Mixed AC/DC Networks with FACTS

It is probable that future power transmission systems will contain more HVDC-VSC links (High Voltage Direct Current-Voltage Source Converter) leading to a growing complexity in the study of its problem and so do the transient stability problems which are yet to be determined. In this context, this paper presents an efficient method to resolve this problem. Its main objective consists of improving transient stability of the AC/DC (Alternating Current/ Direct Current) power system network using FACTS (Flexible Alternating Current Transmission Systems). The overall performance of the FACTS was evaluated in an IEEE 14 bus test system by nonlinear simulations carried out using Matlab environment to check the performance of FACTS (TCSC, Thyristor Controlled Series Capacitor). The obtained results showed the effectiveness and robustness of FACTS in improving the transient stability of the systemt.

Improving the Transient Stability of the Mixed AC/DC Networks with FACTS

It is probable that future power transmission systems will contain more HVDC-VSC links (High Voltage Direct Current-Voltage Source Converter) leading to a growing complexity in the study of its problem and so do the transient stability problems which are yet to be determined. In this context, this paper presents an efficient method to resolve this problem. Its main objective consists of improving transient stability of the AC/DC (Alternating Current/ Direct Current) power system network using FACTS (Flexible Alternating Current Transmission Systems). The overall performance of the FACTS was evaluated in an IEEE 14 bus test system by nonlinear simulations carried out using Matlab environment to check the performance of FACTS (TCSC, Thyristor Controlled Series Capacitor). The obtained results showed the effectiveness and robustness of FACTS in improving the transient stability of the systemt.

Design of a Stable DC Voltage Source and Computer Controlling of It Using an Indigenously Developed All-Digital Addressing-Cum-Control Hardware

We have developed a digitally operated addressing and control module (DACM) for addressing and controlling of equipment from a remote computer using a communication protocol developed in-house. This is useful for automation of an experiment that uses multiple equipment in a pre-decided synchronized manner. We also report design of a multipurpose high voltage direct current (DC) source that provides output of 0–100 V with an average stability of 1.90 (36) mV and has minimum step size of 3 mV. Operation of the DACM is examined by selecting the desired equipment, which in this case is the dc source, and remotely controlling its output from a computer. We also show that this can generate voltage with different waveforms within a 0–10 Hz frequency bandwidth. Such computer controlled ultra-stable high voltage sources tuneable to any arbitrary waveforms at low frequencies have many applications such as, driving a piezo for smooth scanning of laser frequencies, tuning length of a Fabry–Perot cavity, biasing of the electrodes in an ion trap and so on.

Theoretical and Experimental Investigation of Switching Ripple in the DC-Link Voltage of Single-Phase H-Bridge PWM Inverters

Direct current (DC)-link voltage ripple analysis is essential for determining harmonic noise and for DC-link capacitor design and selection in single-phase pulse-width modulation (PWM) inverters. This paper provides an extensive theoretical analysis of DC-link voltage ripple for full-bridge (H-bridge) inverters, with simulation and experimental verifications, considering a DC source impedance (non-ideal DC voltage source). The DC voltage ripple amplitude is theoretically estimated as a function of the output current, both amplitude and phase angle, and the modulation index. It consists of a switching frequency component and a double-fundamental frequency component (i.e., 100 Hz), thereby both components are considered in the analysis. In particular, the peak-to-peak distribution, maximum amplitude, and root mean square (RMS) values of the voltage switching ripple over the fundamental period are obtained. Based on the DC voltage requirements, simple and effective guidelines for designing DC-link capacitors are obtained.