Journal articles on the topic 'Current voltage and power voltage characteristics'
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1
Qasim, Ahmed, Fadhil Tahir, and Ahmed Alsammak. "Voltage Sag, Voltage Swell and Harmonics Reduction Using Unified Power Quality Conditioner (UPQC) Under Nonlinear Loads." Iraqi Journal for Electrical and Electronic Engineering 17, no. 2 (September 19, 2021): 140–50. http://dx.doi.org/10.37917/ijeee.17.2.16.
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In light of the widespread usage of power electronics devices, power quality (PQ) has become an increasingly essential factor. Due to nonlinear characteristics, the power electronic devices produce harmonics and consume lag current from the utility. The UPQC is a device that compensates for harmonics and reactive power while also reducing problems related to voltage and current. In this work, a three-phase, three-wire UPQC is suggested to reduce voltage-sag, voltage-swell, voltage and current harmonics. The UPQC is composed of shunt and series Active Power Filters (APFs) that are controlled utilizing the Unit Vector Template Generation (UVTG) technique. Under nonlinear loads, the suggested UPQC system can be improved PQ at the point of common coupling (PCC) in power distribution networks. The simulation results show that UPQC reduces the effect of supply voltage changes and harmonic currents on the power line under nonlinear loads, where the Total Harmonic Distortion (THD) of load voltages and source currents obtained are less than 5%, according to the IEEE-519 standard.
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Islam, Mirwazul, and Grigory Simin. "Compact Model for Current Collapse in GaN-HEMT Power Switches." International Journal of High Speed Electronics and Systems 25, no. 01n02 (March 2016): 1640001. http://dx.doi.org/10.1142/s0129156416400012.
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We present a simple yet accurate model describing current-voltage characteristics of GaN-HEMT power switches in presence of carrier trapping often referred to as current collapse. The model accounts for time-dependent changes in the source-gate and gate-drain resistances after application of high drain voltage. The model also has a regime describing ‘fast’ current voltage characteristics when the applied voltage swing occurs within a period of time much shorter than the characteristic trapping – detrapping times. The model is written in Verilog-A and can be implemented in SPICE-type circuit simulators.
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Odzaev, Vladimir B., Aliaksandr N. Pyatlitski, Uladislau S. Prasalovich, Natalya S. Kovalchuk, Yaroslav A. Soloviev, Dmitry V. Shestovski, Valentin Yu Yavid, and Yuri N. Yankovski. "Electrophysical characteristics of power MOSFETs additionally implanted with nitrogen ions." Journal of the Belarusian State University. Physics, no. 3 (September 29, 2022): 81–92. http://dx.doi.org/10.33581/2520-2243-2022-3-81-92.
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The electrical characteristics of power MOSFETs additionally implanted with nitrogen ions have been studied. Ion implantation of nitrogen was carried out through a protective oxide of 23 nm thickness with energies of 20 and 40 keV and doses of 1 ⋅ 1013‒5 ⋅ 1014 cm–2. Rapid thermal annealing was carried out at temperature of 900 or 1000 °C for 15 s. It has been established that nitridisation of the gate dielectric makes it possible to reduce the noise of the gate leakage currents and their dispersion. In the direct order of heat treatment (first rapid thermal annealing, and then the removal of the protective oxide), for samples prepared with an additional operation of nitrogen ion implantation, there is an increase in the threshold voltage compared to control samples. The capacitance of the gate dielectric in the case of implantation of nitrogen ions in the direct order of heat treatment is less than for control samples. It has been established that in the direct order of rapid thermal annealing, the doses of nitrogen ion implantation do not cause significant changes in the maximum value of the current-voltage slope. At the same time, in all studied cases, there is a shift in the maximum value of the current-voltage slope towards higher gate voltages. In the reverse order of heat treatment (first the removal of the protective oxide, and then rapid thermal annealing), there are no significant differences in the value of the threshold voltage for the samples created with additional nitrogen implantation and the control ones. The maximum value of the current-voltage slope also does not experience significant changes. It is shown that in the voltage range from – 0.15 to 0 V, the drain current of nitrogen-implanted samples manufactured using the direct order of heat treatment is higher than for control samples, and the drain current of nitrogen-implanted samples obtained with the reverse order of heat treatment it is lower compared to control samples. Results are explained by a decrease in the density of surface states at the Si – SiO2 interface in MOS-structures created using an additional operation of nitrogen ion implantation in the direct order of heat treatment.
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Shim, Yo-Shep. "Electrical Characteristics of Underwater Human Body Model in Charging Power Facility." Korean Society of Technical Education and Training 25, no. 3 (September 30, 2020): 25–31. http://dx.doi.org/10.29279/kostet.2020.25.3.25.
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In this study, the electrical simulation of electric shock accidents at a voltage of 220 V was investigated using Andrew s body model in water. The constructed circuit consisted of Andrew s body model. The voltages measured on a hand, breast, waist, were compared with the electric currents measured on the hand, breast, and waist considering the safety limit of an electric current passing through the body. From the results, it can be understood that the magnitude and wave of electric current passing through the body affect the heart s control of a signal, which directly affects the ventricle of the heart in detail. It comes from the simulation through the ATP -Draw program. This study could be useful in solving safety issues for the electric angle limit by measuring flooding body resistance, as well as the voltage and current passing through each part.
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Matsuda, Takuma, Takashi Yokoseki, Satoshi Mitomo, Koichi Murata, Takahiro Makino, Hiroshi Abe, Akinori Takeyama, et al. "Change in Characteristics of SiC MOSFETs by Gamma-Ray Irradiation at High Temperature." Materials Science Forum 858 (May 2016): 860–63. http://dx.doi.org/10.4028/www.scientific.net/msf.858.860.
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Radiation response of 4H-SiC vertical power Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) was investigated at 150°C up to 10.4 MGy. Until irradiation at 1.2 MGy, the drain current – gate voltage curves of the SiC MOSFETs shifted to the negative voltage side, and the leakage of drain current at gate voltages below threshold voltage increased with increasing absorbed dose. However, no significant change in the electrical characteristics of SiC MOSFETs was observed at doses above 1.2 MGy. For blocking characteristics, there were no degradations of the SiC MOSFETs irradiated at 150°C even after irradiated at 10.4 MGy.
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Cho, Min Su, Hye Jin Mun, Sang Ho Lee, Hee Dae An, Jin Park, Jaewon Jang, Jin-Hyuk Bae, and In Man Kang. "Design and Analysis of DC/DC Boost Converter Using Vertical GaN Power Device." Journal of Nanoscience and Nanotechnology 21, no. 8 (August 1, 2021): 4320–24. http://dx.doi.org/10.1166/jnn.2021.19395.
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In this study, a high-performance vertical gallium nitride (GaN) power transistor is designed by using two-dimensional technology computer-aided design simulator. The vertical GaN transistor is used to analyze the DC/DC boost converter. The systems requiring high voltages of 1000 V or more, such as electric vehicles, need wide devices to achieve a high breakdown voltage when using conventional power devices. However, vertical GaN transistors can be fabricated with small device area and high breakdown voltage. The proposed device has an off-current of 4.72×10−10 A/cm2, an on-current of 17,528 A/cm2, and a high breakdown voltage of 1,265 V due to good gate controllability and the very long gate-to-drain length. Using the designed device, a boost converter that doubles the input voltage was constructed and is characteristics were examined. The designed boost converter obtained an output voltage of 1,951 V and the voltage conversion efficiency was considerably high at 97.55% when the input voltage was 1,000 V.
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Bolaño Martínez, Adrián, Isaac Jimenez Navarro, Vladimir Sousa Santos, Enrique Ciro Quispe, and Pablo Daniel Donolo. "MATLAB/Simulink modeling of electric motors operating with harmonics and unbalance." International Journal of Electrical and Computer Engineering (IJECE) 12, no. 5 (October 1, 2022): 4640. http://dx.doi.org/10.11591/ijece.v12i5.pp4640-4648.
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This paper aims to present a simulation model for the analysis of the operational characteristics of electric motors (EMs). The model was developed on the Simulink platform of the MATLAB program and allows analysis in supply conditions with harmonics and voltage unbalance. The contribution of the model is that it considers the mechanical losses and provides for the study of the effect of each component of the electrical sequence of the harmonics and the voltage unbalance on the electromechanical characteristics of the EM. The model developed was tested in a 37.3 kW EM, operating under four power supply conditions: balanced sinusoidal voltages, balanced non-sinusoidal voltages (i.e., harmonics), unbalanced sinusoidal voltages, and non-sinusoidal unbalanced voltages. The results showed that under the conditions of harmonics and unbalance, the efficiency was reduced by 2%, respectively and that with the combined effects, the efficiency decreased by 4%. The results made it possible to quantify, from the current, voltage, and electrical power values of each sequence, the adverse effects caused by voltage unbalance and harmonics.
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Chen, Jinlei, Sheng Wang, Carlos E. Ugalde-Loo, Wenlong Ming, Oluwole D. Adeuyi, Salvatore D’Arco, Salvador Ceballos, et al. "Demonstration of Converter Control Interactions in MMC-HVDC Systems." Electronics 11, no. 2 (January 6, 2022): 175. http://dx.doi.org/10.3390/electronics11020175.
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Although the control of modular multi-level converters (MMCs) in high-voltage direct-current (HVDC) networks has become a mature subject these days, the potential for adverse interactions between different converter controls remains an under-researched challenge attracting the attention from both academia and industry. Even for point-to-point HVDC links (i.e., simple HVDC systems), converter control interactions may result in the shifting of system operating voltages, increased power losses, and unintended power imbalances at converter stations. To bridge this research gap, the risk of multiple cross-over of control characteristics of MMCs is assessed in this paper through mathematical analysis, computational simulation, and experimental validation. Specifically, the following point-to-point HVDC link configurations are examined: (1) one MMC station equipped with a current versus voltage droop control and the other station equipped with a constant power control; and (2) one MMC station equipped with a power versus voltage droop control and the other station equipped with a constant current control. Design guidelines for droop coefficients are provided to prevent adverse control interactions. A 60-kW MMC test-rig is used to experimentally verify the impact of multiple crossing of control characteristics of the DC system configurations, with results verified through software simulation in MATLAB/Simulink using an open access toolbox. Results show that in operating conditions of 650 V and 50 A (DC voltage and DC current), drifts of 7.7% in the DC voltage and of 10% in the DC current occur due to adverse control interactions under the current versus voltage droop and power control scheme. Similarly, drifts of 7.7% both in the DC voltage and power occur under the power versus voltage droop and current control scheme.
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Bolshanyn, G. A. "EQUIVALENTS OF THE PASSIVE EIGHT-EARTH POLAR WITH THREE INPUT AND FIVE OUTPUT CONCLUSIONS." Proceedings of the higher educational institutions. ENERGY SECTOR PROBLEMS 20, no. 9-10 (January 24, 2019): 109–19. http://dx.doi.org/10.30724/1998-9903-2018-20-9-10-109-119.
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Eight-poles of various designs, including an eight-terminal network with three input and five output terminals, are needed to replace some power objects. Especially when only the input and output characteristics of electrical energy are of interest. The paper presents the eightterminal network equations with three input and five output terminals, establishing a connection between these characteristics. Equations of the A-form establish a connection between the input and output voltages and currents; the B-form equations establish a connection between the output and input voltages and currents; G-form equations establish a connection between the input current, output voltages and output voltage, output currents; H-form equations establish the relationship between the input voltage, output currents and output current, output voltages; the Yform equations establish a connection between the input and output currents and the input and output voltages; The Z-form equations establish the relationship between the input and output voltages and the input and output currents. When implementing these equations, attention should be paid to the difference in the directions of the currents in each individual case.
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Sultanov, M. M., A. V. Strijichenko, and S. A. Yanchenko. "Analysis of the impact of non-sinusoidal voltage levels in the power grid of apartment buildings on the reliability and efficiency of transformers." Safety and Reliability of Power Industry 15, no. 4 (February 9, 2023): 278–83. http://dx.doi.org/10.24223/1999-5555-2022-15-4-278-283.
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The effects of mass implementation of energy-saving lighting on the permissible level of loading of the supply transformer were analyzed. The influence of non-sinusoidal voltages and currents on transformer wear was analyzed. Distortions of sinusoidal shape of voltages and currents lead to additional power losses in transformer. They cause heating of the insulation and windings of the transformer, increased losses and accelerated wear and tear. Higher harmonic components of voltage and current in a 0.4 kV network are caused by the presence of various energy-saving lighting lamps with non-linear volt-ampere characteristic, which include compact fluorescent and LED light sources. As a result, the transformer designed to operate at a frequency of 50 Hz experiences an additional adverse effect in the form of power losses and accelerated wear of electrical insulation, which leads not only to the deterioration of its technical and economic performance characteristics, but also to a significant decrease in reliability associated with the influence of higher harmonic components of voltage and current on equipment failure. It is shown that the lack of power factor correction schemes for low-power compact fluorescent and LED lamps causes the growth of nonsinusoidal voltage and current as they spread, which in turn causes the need to adjust the limit load of transformers to ensure their rated thermal mode. One way to maintain operational reliability under such conditions is to limit the transformer load depending on the level of higher harmonics in the network, as well as to predict the residual life of the operating transformer. Measuring the values of current transformer load and current levels of higher harmonic components of voltage and current will allow not only to calculate an acceptable load factor of the transformer (for the condition of insulation wear), but also to estimate the current residual life of transformer equipment using a neural network model.
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Hung, Bui Ngoc, and Lidiia I. Kovernikova. "Analyzing the potential for using active filters to reduce voltage nonsinusoidality in the electric power supply system of a coal open-cut in Vietnam." E3S Web of Conferences 114 (2019): 04006. http://dx.doi.org/10.1051/e3sconf/201911404006.
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Coal mining is one of the important economic sectors in Vietnam. Power supply systems of coal mines and open-cuts are complex. They have multiple levels of voltages and different types of loads. New electrical equipment usually works alongside with the equipment that is obsolete and worn-out. Power supply systems of industrial areas of Vietnam where coal is mined are characterized by the low power quality. In Vietnam the indices which characterize the distortion of both voltage and current waveforms have standard values. The article presents the findings upon the analysis of a power supply system of a coal open-cut in Vietnam and the electrical equipment of the coal sorting plant along with the results of the experimental studies of power quality indices and the non-sinusoidal mode parameters. The measurement analysis has shown that the indices of the 5-th and 7-th harmonics of voltage were over the limits. There are interharmonics in voltages and currents. The article analyzes the characteristics of active filters. It is possible to improve the power quality by using an active filter which generates both reactive power to increase the load power factor and harmonic and interharmonic currents to reduce the degree of voltage and current waveform distortion.
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Różański, Andrzej. "Determination of the current-voltage characteristics of the photovoltaic cells using the CoachLabII+ measuring console." Journal of Automation, Electronics and Electrical Engineering 4, no. 2 (December 31, 2022): 31–38. http://dx.doi.org/10.24136/jaeee.2022.010.
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The Coach6 software and the CoachLabII+ measuring console coupled with a computer and equipped with appropriate voltage and current sensors were used to determine the current-voltage and power-voltage characteristics of the photovoltaic cells. The current-voltage and power-voltage characteristics for a single cell and cells connected in series and in parallel were tested depending on the light intensity. Using a simplified theoretical model of a photovoltaic cell based on the one-diode equivalent circuit and Shockley diode equation, the ideality factor, diode saturation current and source current were determined, fitting the appropriate theoretical relationship to the measurement results. Based on the current-voltage and power-voltage characteristics, the short-circuit current, open circuit voltage, maximum power, fill factor, conversion efficiency and load resistance were determined. The dependence of the determined parameters on the light intensity was discussed.
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Sarala, P., S. F. Kodad, and B. Sarvesh. "Power Factor Correction with Current Controlled Buck Converter for BLDC Motor Drive." International Journal of Power Electronics and Drive Systems (IJPEDS) 8, no. 2 (June 1, 2017): 730. http://dx.doi.org/10.11591/ijpeds.v8.i2.pp730-738.
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Brushless DC motor is a synchronous machine that makes use of electronic commutation instead of mechanical commutator. Brushless DC motors makes use of inverter encompassing static switches for its operation. A simple bridge converter when used for BLDC drive as front end converter makes input source power factor to get reduced which is unacceptable in the power system. To avoid the distortions in the source voltage and source currents, Buck converter which was used as power factor correction (PFC) converter in this paper to improve the power factor. Presence of power electronic converters deteriorates system power factor effecting overall system performance. This paper presents buck converter for power factor correction in brushless DC motor drive system. Buck converter is operated with current control strategy rather to conventional voltage follower control. Simulation model was obtained using MATLAB/SIMULINK software and the brushless DC motor performance characteristics were shown for conditions with different DC link voltages and step variation in DC link voltage. Total harmonic distortion in source current was also presented.
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Cherno, O. O., A. P. Hurov, and A. V. Ivanov. "ENERGY CHARACTERISTICS OF THE ELECTROMAGNETIC VIBRATION DRIVE WITH PULSE POWER SUPPLY OF VIBRATOR COILS." Tekhnichna Elektrodynamika 2023, no. 2 (February 23, 2023): 53–60. http://dx.doi.org/10.15407/techned2023.02.053.
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Vibrating equipment provides various technological processes, such as transportation, separation, compaction of mixtures. The electromagnetic drive is usually used in vibrating conveyors, feeders and other devices where vibration parameters are automatically controlled. Increasing the energy efficiency of such devices is an important task. The paper examines the influence of the power supply voltage on the energy characteristics of the electromagnetic vibration drive and determines the most effective voltage form. To do this, an analysis of factors affecting the efficiency of the drive was carried out. It was found that one of the factors is the time interval between the maximum current and the minimum value of the air gap, and increasing the efficiency is possible by reducing this interval by forming bipolar rectangular voltage pulses with maximum amplitude, which create narrow sharp pulses of the vibrator coil current. As a result of the numerical modeling of the processes in the drive, it was found that with increasing power, current pulses cause short-term deep saturation of steel, which leads to increased losses and reduced efficiency. Therefore, a zero voltage interval was added between the positive and negative voltage pulses, which limits the peak current values. The simulation of the processes in the vibration drive with the voltage supply of the proposed form was carried out, its energy characteristics were calculated: the dependence of the efficiency on the frequency at different load values, the dependence of the maximum values of the efficiency on the power. It was established that the use of pulsed power supply makes it possible to increase the efficiency of the drive up to 80% in the power range from 0.25 of the nominal value to the nominal one, which is on average 10% more compared to sinusoidal voltage. The dependences of frequency and zero voltage interval optimal values (according to the criterion of maximum efficiency) on power, which can be used in automatic control of the drive, have been obtained. References 10, figures 9, tables 2.
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Lan, Yu Dan, and Li Ming He. "Electrical Characteristics Investigation of Transient Plasma Ignition." Applied Mechanics and Materials 110-116 (October 2011): 503–7. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.503.
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A pseudo-spark based high repetition pulse generator is used, and a rapid charger (3μF) is used for repetitive discharge, and the frequency of typical discharge is 10 kHz. The pulse generator can provide pulse with duration of 1~2μs, which can be generated at 10~100 kHz maximum repetition rate in burst mode, with amplitudes up to 140 kV and 7 J of energy per ignition pulse. This paper studies the changing laws of voltage and current in TPI under different electrodes and discharge voltages. The result indicates that the use of screw thread electrode can increase the discharge times of TPI, reduce applied voltage without reducing the peak burst power. With the same time, TPI can raise the pulse energy and reduce pulse time by increasing voltage.
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Cai, Wei, Hui Min He, Jian Wei Wang, and Shao Ze Su. "A Control Strategy for the Grid-Side Converter of the Directly-Driven Wind Turbine with PM Synchronous Generator under Unbalanced Grid Voltage." Advanced Materials Research 816-817 (September 2013): 669–77. http://dx.doi.org/10.4028/www.scientific.net/amr.816-817.669.
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A mathematical model of the full power grid-connecting converter at grid side for permanent magnet synchronous generator (PMSG) under unbalanced grid conditions is built, double-frequency oscillation mechanism on DC voltage is analyzed, and the influence of active power ripple of grid-connecting impedance on dual current control is discussed. To suppress the double-frequency oscillation on DC voltage, and take the grid-connected impedance on active power into account, a dual current control strategy, which based on respectively orientating positive-and negative-sequence voltages,is proposed, and introduced the correction value of active power ripple of grid-connecting impedance to correct reference current of proposed control strategy. Simulation results show that the proposed control strategy can effectively control positive and negative-sequence currents,eliminate the DC voltage double-frequency oscillation,and improve harmonic characteristic of grid-connected current.
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Karimov, A. V., A. Z. Rakhmatov, O. A. Abdulkhaev, U. H. Aripova, A. Yu Khidirnazarova, and Sh M. Kuliyev. "Controlling voltage drops in silicon diodes by electron irradiation and thermal treatment." Технология и конструирование в электронной аппаратуре, no. 4 (2018): 33–37. http://dx.doi.org/10.15222/tkea2018.4.33.
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High-frequency limiting rectifier diodes are used in power sources for rectifying alternating current, in protective elements of radio-electronic equipment, and in switching devices. They are the basis of energy-saving devices, meeting the high requirements for power limit and performance. The main task in the manufacturing process of high-frequency diodes is to ensure the low leakage current and the optimum value of the forward voltage drop which can be compared with the contact potential difference of the p–n junction. This paper is devoted to studying the effect of radiation exposure and subsequent heat treatment on the current-voltage and capacitance characteristics of high-frequency silicon diodes. The authors studied p+–p–n–n+ diodes made of n-type KEF-4 (ÊÝÔ-4) silicon wafers with an initial thickness of 235 µm. Radiation processing was performed using an ELU-6 (ÝËÓ-6) linear electron accelerator. The integral flux of “fast” electrons ranged from 1,0∙1015 to 2,6∙1017 cm–2, energy was 1.5 MeV, density was 1,7∙1011 — 5,5∙1013 cm–2∙s –1. Heat treatment was performed for 5 hours at a temperature of 90°C in a special chamber. The studies have shown that heat treatment lead to a shift of the forward current-voltage characteristic to a region of lower voltages (i.e., a given current can be reached at a lower voltage); at low current values, however, the voltage drop may increase after heat treatment. Reverse current decreased fivefold, resulting in a decrease in power output. At the same time, the temporal characteristics of the diode could also be improved by reducing the capacitance (to one order of magnitude)
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Sudiharto, Indhana, Farid Dwi Murdianto, and Ayu Wulandari. "Adaptive charging control using ANN-PID controllers on multiple DC loads with varying battery voltages." International Journal of Power Electronics and Drive Systems (IJPEDS) 13, no. 1 (March 1, 2022): 620. http://dx.doi.org/10.11591/ijpeds.v13.i1.pp620-630.
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Various rechargeable electronic devices currently have batteries with different capacities and voltages, while the available chargers are generally fixed for one device. This is considered less effective because different types of electronic devices will require different battery chargers. Therefore, the adaptive power charge is needed to recharge batteries with different voltages and capacities through a single port by adjusting the type of load connected. This system uses buck converter with duty cycle settings through microcontrollers to lower the input voltage to variable output voltage. When the load is connected, the limit switch will be depressed and the system will start the duty cycle tracking process. The voltage will be increased gradually until the current is read at a certain value to identify the load. After the current reads the duty cycle stops tracking, then the current and voltage characteristics are used as input variables for the artificial neural network (ANN) algorithm to determine the target setpoint voltage to be executed by the proportional, integral and derivative (PID) controller. The designed adaptive power charge can identify the connected load accurately. The average ANN output error is 1.46e-4% and the average PID controller error is 6.4e-2%. The system can reach a steady state at 0.01 s.
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Gupta, Maneesha, Richa Srivastava, and Urvashi Singh. "Low Voltage Floating Gate MOS Transistor Based Differential Voltage Squarer." ISRN Electronics 2014 (February 9, 2014): 1–6. http://dx.doi.org/10.1155/2014/357184.
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This paper presents novel floating gate MOSFET (FGMOS) based differential voltage squarer using FGMOS characteristics in saturation region. The proposed squarer is constructed by a simple FGMOS based squarer and linear differential voltage attenuator. The squarer part of the proposed circuit uses one of the inputs of two-input FGMOS transistor for threshold voltage cancellation so as to implement a perfect squarer function, and the differential voltage attenuator part acts as input stage so as to generate the differential signals. The proposed circuit provides a current output proportional to the square of the difference of two input voltages. The second order effect caused by parasitic capacitance and mobility degradation is discussed. The circuit has advantages such as low supply voltage, low power consumption, and low transistor count. Performance of the circuit is verified at ±0.75 V in TSMC 0.18 μm CMOS, BSIM3, and Level 49 technology by using Cadence Spectre simulator.
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Tsai, Wen Chang. "Design and Implementation of a Voltage Booster Circuit for High-Pressure Injector Drives in GDI Engines." Applied Mechanics and Materials 128-129 (October 2011): 1367–70. http://dx.doi.org/10.4028/www.scientific.net/amm.128-129.1367.
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A DC/DC voltage booster circuit is essential to design for the high-pressure (H.P.) injector driving circuit since the power supply voltages for various H.P. injectors are DC 60~90 V rather than DC 12~14V battery voltages. The DC 12~14V battery voltages have to be boosted up to the stable DC 60~90 V voltages supply for being able to drive various H.P. injectors. The new H.P. injector driving circuit consists of a voltage booster circuit and an originally designed three-stage power MOSFETs injector driving circuit to control the dc-link power supply voltage. The dynamic performance of a H.P. injector driven by the designed electrical driving circuit with the voltage booster are simulated and analyzed. The stability and electrical characteristics for the voltage booster under various injection pulse durations and engine speeds are investigated. The fuel injection quantities, supply voltages and injector driving currents of the H.P. injector fed by the new injector driving circuit is illustrated and analyzed in the paper. The experimental results show that this injector driving circuit with a newly designed voltage booster is capable of operating stably to drive the H.P. injector and obtain the accurate fuel injection quantities in the air-fuel ratio control of engines.
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Polajžer, Boštjan, Bojan Grčar, Jernej Černelič, and Jožef Ritonja. "Power-Based Concept for Current Injection by Inverter-Interfaced Distributed Generations during Transmission-Network Faults." Applied Sciences 11, no. 21 (November 6, 2021): 10437. http://dx.doi.org/10.3390/app112110437.
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This paper analyzes the influence of inverter-interfaced distributed generations’ (IIDGs) response during transmission network faults. The simplest and safest solution is to switch IIDGs off during network faults without impacting the network voltages. A more elaborate and efficient concept, required by national grid codes, is based on controlling the IIDGs’ currents, involving positive- and negative-sequence voltage measured at the connection point. In this way the magnitude and phase of the injected currents can be adjusted, although the generated power will depend on the actual line voltages at the connection point. Therefore, an improved concept is proposed to adjust IIDGs’ fault current injection through the required active and reactive power, employing the same voltage characteristics. The proposed, i.e., power-based concept, is more definite than the current-based one, since the required power will always be generated. The discussed concepts for the fault current injection by IIDGs were tested in different 110-kV networks with loop and radial topologies, and for different short-circuit capabilities of the aggregated network supply. Based on extensive numerical calculations, the power-based concept during transmission networks faults generates more reactive power compared to the current-based concept. However, the voltage support by IIDGs during transmission networks faults, regardless of the concept being used, is influenced mainly by the short-circuit capability of the aggregated network supply. As regards distance protection operation, it is influenced additionally by the network topology, i.e., in radial network topology, the remote relay’s operation can be delayed due to a largely seen impedance.
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Vanin, Valery, Alexandr Bulychov, Maxim Popov, Olga Vasilyeva, and Maria Shakhova. "About influence of non-sinusoidal currents and voltages on the amount of the electric energy." MATEC Web of Conferences 245 (2018): 06009. http://dx.doi.org/10.1051/matecconf/201824506009.
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The results of measurements of the harmonics components of the current, voltage, power of harmonics at the point of connection of electric receivers with a non-linear voltage-current characteristic are considered. It is shown that the amount of electric energy including the non-sinusoidality of the currents and voltages consumed by the non-linear load is less than the amount of the fundamental frequency energy. The difference between them is the harmonic distortion energy that causes extra losses to the electric networks. The voltage harmonic distortions at the measurement point exceed the normative values for 0.4 kV electric networks.
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Ramya, R., S. Piramasubramanian, G. Ganesh Madhan, and D. Rebecca. "Effect of Collector Voltage on the Large and Small Signal Modulation Characteristics of 980 nm Transistor Laser." Defence Science Journal 70, no. 5 (October 8, 2020): 529–33. http://dx.doi.org/10.14429/dsj.70.16341.
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Theoretical analysis of Transistor Laser is carried out and the static and frequency responses for different collector voltages, under common emitter configuration are determined. The threshold current (Ith) is observed as 33mA and it increases linearly with reverse collector to base voltage (VCB). Meanwhile, the output optical power is found to decrease proportionately when VCB is increased. A maximum of 18.7GHz modulation bandwidth is observed when an input base current of 95 mA is applied at a fixed value of VCB (1V). The modulation bandwidth is found to decrease with increase in reverse VCB. The turn on delay increases with collector voltage. However, it decreases with increase in base current.
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Denysiuk, S., and T. Bazyuk. "EVALUATION OF ADDITIONAL LOSSES AND EFFICIENCY ELECTRICITY CONSUMPTION REGULATION IN LOCAL POWER SUPPLY SYSTEMS." POWER ENGINEERING: economics, technique, ecology, no. 3 (April 6, 2020): 7–21. http://dx.doi.org/10.20535/1813-5420.3.2020.228596.
Full textAbstract:
Peculiarities of estimation of total energy losses in electric networks and estimation of nature of electricity consumption in local power supply systems (LES) are given. The structure of additional electricity losses in LES in the presence of higher harmonics of current and voltage is carried out, the generalized schedule of instantaneous functions of current i(t), voltage u(t), and power p(t) on components. The offered indicators of an estimation of the performance of criterion of a minimum of losses of the electric power in LES allow to estimate levels of distortion of power processes at consideration both exchange processes, and at the analysis of additional losses of the electric power. The accuracy of measuring the integrated characteristics of energy exchange depending on the available levels of distortion of voltage and current signals is considered. It is shown that in order to take into account the influence of higher harmonics on the total power consumption, it is necessary to determine the change of Frize QFpower as an indicator of additional electricity losses in the presence of non-sinusoidal currents and voltages in at different ratios between the value of current and voltage of the first and higher harmonics. The evaluation of the efficiency of power consumption regulation using the Frize QF power at an arbitrary time interval, as well as the corresponding current distribution into active and reactive components are considered. The peculiarities of increasing the efficiency of power consumption regulation in LES at the cyclic change of generator parameters and load are analysed.
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Matsumura, Toshiro, Masumi Tsukamoto, Akihiro Tsusaka, Kazuto Yukita, Yasuyuki Goto, Yasunobu Yokomizu, Kento Tatewaki, et al. "Line-End Voltage and Voltage Profile along Power Distribution Line with Large-Power Photovoltaic Generation System." International Journal of Photoenergy 2019 (March 24, 2019): 1–8. http://dx.doi.org/10.1155/2019/1263480.
Full textAbstract:
In recent years, the introduction of the photovoltaic generation system (PV system) has been increasing by promoting the use of renewable energy. It has been feared that the reverse current from the PV system may cause an unacceptable level of voltage rise at the interconnection node in the power distribution system. This paper discusses the effects of the reverse current on the voltage rise and fall characteristics of the interconnection node and the voltage profiles along the power distribution line. When the line current on the circuit is small, the voltage on the line monotonically increases from the sending end to the receiving end. When a relatively large current flows, it causes a voltage reduction near the distribution substation. Furthermore, on the basis of the voltage aspects in the power distribution system with a large PV system, the allowable limits of the line current and the output power from PV system are investigated.
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Pavithra, K., H. Pooja, D. Tamilselvan, and T. D. Sudhakar. "Solar power based positive output super-lift Luo converter using fuzzy logic controller." Journal of Physics: Conference Series 2040, no. 1 (October 1, 2021): 012034. http://dx.doi.org/10.1088/1742-6596/2040/1/012034.
Full textAbstract:
Abstract Photovoltaic (PV) power generation is employed to meet the increasing demand for energy and of cleaner form. Though renewable and high energy using PV can be produced, they have certain disadvantages. PV cells have a low voltage (approx. 0.5V) rating and they have to be connected in series when higher voltage is required. These cells when connected in series should have identical electrical characteristics to avoid ripples in the output voltage and current, but it is not possible practically. To avoid this miss-match, converter circuits are employed. The major drawbacks in most power converters are reduced voltage gain and their tendency to generate harmonics in the supply system and the load circuit. To overcome these limitations, a positive output super-lift Luo converter is designed. A Positive Output Super Lift Luo converter (POSLC) is a powerful DC-DC converter where the voltage is converted from positive source voltage to positive load voltage as it produces positive voltages of comparatively higher ranges than those of conventional types. The super-lift technique also overcomes the effect of parasitic elements and thus minimizing the ripples in the output voltage and current. In addition to this, the voltage build-up can be achieved by implementing the super-lift technique where the output voltage rises in geometric progression with increased voltage transfer gain and high power density. In this paper fuzzy control is used to produce better-controlled voltage and a more refined output. The performance of POSLC with and without implementation of fuzzy control has been successfully simulated and verified using MATLAB/SIMULINK as well simulation model also developed and analyzed with Proteus package.
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Саидов, А. С., А. Ю. Лейдерман, Ш. Н. Усмонов, and У. П. Асатова. "Особенности вольт-амперной характеристики гетероструктуры n-GaP--p-(InSb)-=SUB=-1-x-=/SUB=-(Sn-=SUB=-2-=/SUB=-)-=SUB=-x-=/SUB=-." Письма в журнал технической физики 46, no. 22 (2020): 23. http://dx.doi.org/10.21883/pjtf.2020.22.50303.18257.
Full textAbstract:
The current-voltage characteristic of n-GaP--p-(InSb)1-x(Sn2)x (0 ≤ х ≤ 0.05) heterostructures has been studied. It has been shown that at low voltages V < 0.5 V, the current-voltage characteristic is described by the exponential law: I = I0exp (qV /ckT), and at large ones from 0.5 to 1.8 V power laws: I = A*V m with different values of the coefficient A and exponent m at various voltages. At higher voltages - from 2.10 to 2.48 V, a sublinear part is observed, which is described by the law: V= V0*exp(Iad / S).
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Lee, Seongjun, Namgyu Lim, Wonseon Choi, Yongtak Lee, Jongbok Baek, and Jungsoo Park. "Study on Battery Charging Converter for MPPT Control of Laser Wireless Power Transmission System." Electronics 9, no. 10 (October 21, 2020): 1745. http://dx.doi.org/10.3390/electronics9101745.
Full textAbstract:
Herein, the voltage and current output characteristics of a laser photovoltaic (PV) module applied to a wireless power transmission system using a laser beam are analyzed. First, an experiment is conducted to obtain the characteristic data of the voltage and current based on the laser output power of the laser PV module, which generates the maximum power from the laser beam at a wavelength of 1080 nm; subsequently, the small-signal voltage and current characteristics of the laser PV module are analyzed. From the analysis results, it is confirmed that the laser PV module has a characteristic in which the maximum power generation point varies according to the power level of the laser beam. In addition, similar to the solar cell module, it is confirmed that the laser PV module has a current source and a voltage source region, and it shows a small signal resistance characteristic having a negative value as the operating point goes to the current source region. In addition, in this paper, by reflecting these electrical characteristics, a method for designing the controller of a power converter capable of charging a battery while generating maximum power from a PV module is proposed. Since the laser PV module corresponds to the input source of the boost converter used as the power conversion unit, the small-signal transfer function of the boost converter, including the PV module, is derived for the controller design. Therefore, by designing a controller that can stably control the voltage of the PV module in the current source, the maximum power point, and voltage source regions defined according to the output characteristics of the laser PV module, the maximum power is generated from the PV module. Herein, a systematic controller design method for a boost converter for laser wireless power transmission is presented, and the proposed method is validated based on the simulation and experimental results of a 25-W-class boost converter based on a microcontroller unit control.
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Xu, Haizhen, Changzhou Yu, Fubin Mao, Taotao Hu, Zelin Wu, and Qinglong Wang. "Research on Direct Power Control Strategy Based on Voltage Controlled Virtual Synchronous Generator." Electronics 10, no. 19 (October 3, 2021): 2415. http://dx.doi.org/10.3390/electronics10192415.
Full textAbstract:
To support the “carbon peak and carbon neutrality” goal, new energy is poised to explode, and new energy power generation converter is simultaneously facing new challenges. The conventional current-controlled new energy converter can quickly transmit active power on the DC bus to the power grid. However, for the weak grid, the stability margin of the converter grid-connected system is reduced on the one hand, which can easily cause resonance oscillation; on the other hand, the current controlled converter cannot actively respond to system frequency and voltage fluctuation to offer support. The voltage controlled virtual synchronous generator (VVSG) is used to improve system small signal stability and frequency stability; however, its power response speed is too slow to meet the requirements of fast following power command. Although a voltage/current dual-mode switching control scheme is put forward to achieve characteristics complementary of current controlled converter and voltage-controlled converter, the control structure switching and intermediate variable following is required to realize mode switching, which is prone to large power shocks and switching failures. In view of the problem, a direct power control strategy based on VVSG is proposed. The control structure is raised based on a conventional VVSG outer active power control loop, and the output active power and frequency characteristics are analyzed. Compared with the voltage and current dual-mode control, VVSG with direct power control can perform large inertia characteristic in the weak grid and fast power following characteristics in the strong grid by adjusting λ, and without control structure switching and intermediate variable following. Moreover, the two characteristics can be smoothly transited. In addition, the active support ability of voltage source can be maintained under both characteristics. Finally, the effectiveness of the proposed control strategy is verified through simulation results.
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Journal, Baghdad Science. "Impedance Characteristics of Pulsed Atmospheric Electrical Discharge in Spherical Plasma Switch." Baghdad Science Journal 8, no. 2 (June 12, 2011): 630–37. http://dx.doi.org/10.21123/bsj.8.2.630-637.
Full textAbstract:
A number of pulsed experiments have been carried out using a high-voltage circuit containing R,L, and C in certain arrangements. A spherical spark gap of steel electrodes was used as a high-current switch operated by a voltage of up to 8kV and triggered in both self-triggering and third-electrode triggering modes. Current measurements were carried out by using both current-viewing resistor and Rogowski coils designed for this purpose. Typical current waveforms have shown obvious dominating inductance effect of the circuit components in an underdamped oscillation. The behavior of the circuit impedance was studied by recording both pulsed current peaks and the charging voltages when currents of up to 2.5kA were recorded. The duration of these current pulses were found to extend between 0.1?s and 0.3?s depending on the values of the circuit components as well as the spacing of the spark gap electrodes along which the plasma propagates at atmospheric pressure. Over the whole range of experimental conditions, the average nominal impedance values were ranged between (2-10)? depending on the gap and circuit parameters. Typical damage patterns were observed with average diameters of up to 8.3 mm on the high voltage electrode and 10.5 mm on the grounded sphere resulting from accumulative discharges and power dissipation within the gap.
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Thapa, Bhesh Bahadur, and Raju Bhai Tyata. "Study of Dielectric Barrier Discharge in Air and Estimation of Electron Density and Energy Deposition." Journal of Science and Engineering 7 (December 20, 2019): 1–9. http://dx.doi.org/10.3126/jsce.v7i0.26780.
Full textAbstract:
This paper reports the electrical behaviors of atmospheric pressure plasma reactor with Dielectric Barrier Discharge (DBD) in air medium. The DBD discharge was generated in air at atmospheric pressure using Disc Electrode Geometry (DEG) reactor powered by ac voltage (0-7kV) at a frequency of 24kHz. The glass plates of thickness 1.0mm and 3.0mm were used as dielectric. The current-voltage characteristics were studied for two air gap of 2.0mm and 3.0mm by varying the applied voltages. The numbers of filamentary micro discharges were found as increased in each half cycle with increase in power. The observations of Lissajous figure of applied voltage versus electric current was used for measuring energy deposited by discharge and also compared with calculated value. Lissajous figures clearly show that the energy deposited by discharge was dependent on applied voltage. The electron density of discharge was measured by power balance method. Electron density was found in the order of 1017 per cubic meter.
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AZAROV, Oleksiy, and Anna FIGAS. "THERMOSTABLE REFERENCE CURRENT AND VOLTAGE SOURCES FOR HIGH-LINEAR ANALOGUE-CODE-ANALOGUE SYSTEM." Herald of Khmelnytskyi National University. Technical sciences 311, no. 4 (August 2022): 23–28. http://dx.doi.org/10.31891/2307-5732-2022-311-4-23-28.
Full textAbstract:
DC sources and reference voltage sources are widely used in various electronic devices: analog-to-digital and digital-to-analog converters, DC amplifiers, sample-and-hold devices, stabilized voltage sources, and others. At the same time, the accuracy and temperature characteristics of the latter largely depend on the same characteristics of direct current and voltage sources, which are subject to stringent requirements. There are quite a lot of different approaches to the construction of reference voltage and current source circuits with thermal compensation. The most famous of them – with the use of thermally compensated zener diodes operating in reverse breakdown mode. However, devices based on them have a high power consumption and low efficiency and a high level of noise, and it is difficult to implement temperature drift compensation due to a wide spread of temperature characteristics. The so-called bandgap circuits are also widely used – transistor reference voltage sources, the value of the reference voltage of which is determined by the band gap of the semiconductor. The most famous of them are Vidlar’s bandgaps and Brokau’s bandgaps. The specificity of all bandgap circuits is the rigid binding of the output voltage to the band gap of the semiconductor. The article proposes an alternative approach to the construction of direct current and voltage sources, which consists in the use of circuits of two-pole direct current sources. A new approach to the construction of thermally stable reference current sources based on bipolar transistors using the band gap voltage of a semiconductor and current mirrors is proposed. The principles of operation of the circuits are described and the possibility of achieving thermal compensation is proved. Computer modelling of the static characteristics of the proposed reference current sources, in particular, the temperature drift of the currents, has been carried out. A new approach to the construction of thermally stable reference voltage sources based on bipolar transistors with the use of thermally stable reference current generators is proposed. Analytical expressions are obtained that describe operation of circuits of reference voltage sources according to the proposed approach. A method for increasing the loading capacity of these reference voltage sources is proposed.
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Journal, Baghdad Science. "A Comparative Study on the Electrical Characteristics of Generating Plasma by Using Different Target Sources." Baghdad Science Journal 15, no. 4 (December 9, 2018): 436–40. http://dx.doi.org/10.21123/bsj.15.4.436-440.
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In this research, the electrical characteristics of glow discharge plasma were studied. Glow discharge plasma generated in a home-made DC magnetron sputtering system, and a DC-power supply of high voltage as input to the discharge electrodes were both utilized. The distance between two electrodes is 4cm. The gas used to produce plasma is argon gas which flows inside the chamber at a rate of 40 sccm. The influence of work function for different target materials (gold, copper, and silver), - 5cm in diameter and around 1mm thickness - different working pressures, and different applied voltages on electrical characteristics (discharge current, discharge potential, and Paschen’s curve) were studied. The results showed that the discharge current and potential increase by increasing the applied voltage ranging between 300-700 V. Discharge current increased as working pressure increased in the beginning, and then semi-stabilized (slight increase) starting from 1×100 mbar, while discharge potential decreased at the beginning as working pressure increased and then semi-stabilized at the same point at which discharge current stabilized. The Paschen’s curves were compared with each other. It was concluded that the lower breakdown voltage was associated with lower work function of the (Au, Cu, and Ag) cathode material. Breakdown voltages were (395, 398, and 420) for Ag, Cu and Au respectively.
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Ma, Xi Geng, Jun Tao Xu, and Mao Zeng Lu. "The Voltage Output Characteristics of New 24-Pulse Rectification System under Unbalanced Source Voltage." Advanced Materials Research 433-440 (January 2012): 3820–25. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.3820.
Full textAbstract:
The traditional 6-pulse high-power rectifier has defects such as large harmonic content and low power factor in application. The 24-pulse rectification system based on autotransformer can restrain the harmonics and improve power factor effectively. This paper derivate the input current and output voltage’s characteristics of 24-pulse rectification system under balanced grid. At the same time, the author simulate and analysis various impacts of different situations of unbalanced grid on these two characteristics on the basic of real grid ,which has an important guiding significance on the application of the 24-pulse rectification system.
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Далиев, Х. С., and З. М. Хусанов. "STUDY OF TEMPERATURE EFFECTS IN SILICON STRUCTURES WITH VANADIUM IMPURITIES." SEMOCONDUCTOR PHYSICS AND MICROELECTRONICS 3, no. 5 (October 30, 2021): 1–6. http://dx.doi.org/10.37681/2181-1652-019-x-2021-5-1.
Full textAbstract:
The current-voltage characteristics of Au-nCdS- nSi-pCdTe-Au at 300 K. It was found that the current-voltage characteristics of such structures has three segments: power-law - I∝V2.44, sublinear V∝exp(Jad), and pre-breakdown dependence - I∝V5.55. The concentrations of deep impurities responsible for the appearance of a sublinear section of the current-voltage characteristic. experimental the results are explained on the basis of theoretical ideas about the complex nature recombination processes in such materials.
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Toader, Dumitru, Maria Vintan, Claudiu Solea, Daniela Vesa, and Marian Greconici. "Analysis of the Possibilities of Selective Detection of a Single Line-to-Ground Fault in a Medium Voltage Network with Isolated Neutral." Energies 14, no. 21 (October 26, 2021): 7019. http://dx.doi.org/10.3390/en14217019.
Full textAbstract:
The paper analyses how the characteristics of the medium-voltage network with insulated neutral and the conditions under which the single line-to-ground fault occurs (insulation condition and value of the fault resistance) influence the zero-sequence components of the voltage of the transformer station medium-voltage bus bar, the fault current, the currents of the faulted line and the currents of the other non-faulted power lines connected to the transformer station bus bars. Assuming the waveform of the medium voltage bus voltages in the transformer station is known, the influence of the fault resistance on the total distortion coefficient of the fault current is analysed. This establishes the conditions under which a single line-to-ground fault can be detected by controlling the total distortion coefficient of the fault current and the currents of the fault-free lines. It also examines the conditions under which a single line-to-ground fault can be selectively detected by checking the effective value and direction of flow of the zero-sequence currents of the medium-voltage lines during the fault. The results obtained by the calculation were verified experimentally in the medium voltage network considered in the study. The acceptable differences, considering the degree of accuracy with which the parameters of a medium voltage network are known, between the results obtained by calculation and those obtained experimentally show that the simplifying assumptions accepted for the mathematical models used in the calculation are correct.
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Cheremisin, Vasiliy, and Andrey Nikonov. "Method for improving performance of devices for adjustable reactive power compensation." E3S Web of Conferences 110 (2019): 01010. http://dx.doi.org/10.1051/e3sconf/201911001010.
Full textAbstract:
The article presents a method for selecting the parameters of the current-voltage characteristics of adjustable reactive power compensation devices used at sectioning stations of railway sections electrified by alternating current with a voltage of 27.5 kV. This technique is based on the experience of operating two types of devices in the traction power supply system. Power control of these devices is implemented by the voltage level at the switching point. Selection of the setpoint voltage and slope characteristics was done. The developed method allows increasing the efficiency of devices by eliminating the voltage losses on the active component of traction loads. That will reduce the loss of electricity in the system of traction power supply. Changing the parameters of the characteristics will increase the relationship between the reactive power consumed in the zone and the voltage measured by the devices. Following the results of the formation of the methodology, an example of the choice of characteristics for a real compensation device is presented.
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Zotin, Vitaliy, Alexander Drakin, Sergei Rybalka, Andrey Demidov, and Evgeniy Kulchenkov. "Measuring complex for determining the characteristics of high-voltage silicon carbide Schottky diodes in impulse modes." Applied Physics, no. 6 (December 28, 2021): 67–73. http://dx.doi.org/10.51368/1996-0948-2021-6-67-73.
Full textAbstract:
This paper describes a developed automated research measuring complex that allows one to determine the parameters of currents, voltages and power of silicon carbide Schottky diodes when applied reverse voltage impulses with amplitudes from 400 to 1000 V. The research
measuring complex was tested on DDSH411A91 («GRUPPA KREMNY EL») and C3D1P7060Q (Cree/Wolfspeed) silicon carbide Schottky diodes and allows to determine their
maximum values of the rate of rise of reverse voltage dV/dt (877 V/ns and 683 V/ns). Also, the maximum values of the current rise rate dI/dt were determined for DDSH411A91 (3.24 A/ns)
and C3D1P7060Q (3.72 A/ns) diodes. For the first time it was established that, when a reverse voltage impulse with an amplitude of 1000 V is applied, the maximum values of instantaneous fullpower reach 1419 VA for the DDSH411A91 diode and 1638 VA for the C3D1P7060Q diode.
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Lichtenwalner, Daniel J., Akin Akturk, James McGarrity, Jim Richmond, Thomas Barbieri, Brett Hull, Dave Grider, Scott Allen, and John W. Palmour. "Reliability of SiC Power Devices against Cosmic Ray Neutron Single-Event Burnout." Materials Science Forum 924 (June 2018): 559–62. http://dx.doi.org/10.4028/www.scientific.net/msf.924.559.
Full textAbstract:
High-energy neutrons produced by cosmic ray interactions with our atmosphere are known to cause single-event burnout (SEB) failure in power devices operating at high fields. We have performed accelerated high-energy neutron SEB testing of SiC and Si power devices at the Los Alamos Neutron Science Center (LANCSE). Comparing Wolfspeed SiC MOSFETs having different voltage (900V – 3300V) and current (3.5A – 72A) ratings, we find a universal behavior when scaling failure rates by active area, and scaling drain bias by avalanche voltage. Moreover, diodes and MOSFETs behave similarly, revealing that the SiC drift dominates the failure characteristics for both device types. This universal scaling holds for SiC MOSFETs from other manufacturers as well. The SEB characteristics of Si power IGBT and MOSFET devices show that near their rated voltages failure rates of Si devices can be 10X higher than that of comparable SiC MOSFET devices. Thus, Si devices are more susceptible to SEB failure from voltage overshoot conditions.
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Novikov, I. L., Ya S. Greenberg, V. Schultze, R. Ijsselsteijn, and H. G. Meyer. "Voltage–current and voltage–flux characteristics of asymmetric high TC DC SQUIDs." Physica C: Superconductivity 469, no. 1 (January 2009): 30–38. http://dx.doi.org/10.1016/j.physc.2008.10.007.
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Popović, I., V. Rajović, and M. Zlatanović. "Dynamic Voltage-Current Characteristics of Unipolar Pulse Glow Discharge." Materials Science Forum 494 (September 2005): 315–20. http://dx.doi.org/10.4028/www.scientific.net/msf.494.315.
Full textAbstract:
Introduction of pulse plasma power supply is one of the major contributions to plasma surface engineering. The voltage and current waveforms of nitrogen and nitrogen/hydrogen glow discharges in the vacuum total pressure range from 0.1 to 15 mbar were recorded and analyzed concerning the shape, typical operating values and the influence of surface treatment process parameters. It was found that the waveform shape of the voltage and current contains information on pulse generator output parameters and vacuum system properties during normal glow, hollow cathode discharge and arcing. We have also performed the scoping of dynamic parameters and static characteristic, in order to obtain information for the generator and chamber modeling, to be used in a future plasma materials treatment processes control. The influence of process parameters such as total pressure, cathode temperature and biasing voltage on current-voltage characteristics was also considered.
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Dorozhko, S. V., and M. S. Shaimordanova. "Reduction of current transformers errors of rural electrical networks when operating at low currents." IOP Conference Series: Earth and Environmental Science 996, no. 1 (February 1, 2022): 012016. http://dx.doi.org/10.1088/1755-1315/996/1/012016.
Full textAbstract:
Abstract The peculiarities of agricultural power supply are reduced reliability of power supply, increased voltages, and a three-phase – single-phase power distribution system and reduced quality of voltage at power receivers. A key element in rural electrical networks is the power transformer. To detect the deformation of the windings of the power transformer of rural electrical networks, accurate measurements of the currents in the neutral of this transformer are required. Current transformers installed in the neutral do not provide sufficient accuracy at currents less than 5 % of the nominal. A method is proposed for reducing the current transformer errors when operating at low currents, considering the nonlinearity of the magnetization characteristics of the core. The results of calculating the compensation of errors of a laboratory sample of a current transformer are presented.
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Sui, Yang, Ginger G. Walden, Xiao Kun Wang, and James A. Cooper. "Device Options and Design Considerations for High-Voltage (10-20 kV) SiC Power Switching Devices." Materials Science Forum 527-529 (October 2006): 1449–52. http://dx.doi.org/10.4028/www.scientific.net/msf.527-529.1449.
Full textAbstract:
We compare the on-state characteristics of five 4H-SiC power devices designed to block 20 kV. At such a high blocking voltage, the on-state current density depends heavily on the degree of conductivity modulation in the drift region, making the IGBT and thyristor attractive devices for high blocking voltages.
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NAKATA, SHUNJI, HIROSHI MAKINO, RYOTA HONDA, MASAYUKI MIYAMA, and YOSHIO MATSUDA. "ANALYSIS OF VOLTAGE, CURRENT AND ENERGY DISSIPATION OF STEPWISE ADIABATIC CHARGING OF A CAPACITOR USING A NONRESONANT INDUCTOR CURRENT." Journal of Circuits, Systems and Computers 23, no. 03 (March 2014): 1450039. http://dx.doi.org/10.1142/s021812661450039x.
Full textAbstract:
This paper describes characteristics of stepwise adiabatic charging with an inductor current by controlling switching transistors. An exact analytical resolution is obtained by using a vector comprising a voltage and a current. From a matrix calculation, the voltage and current can be written with solutions of the characteristic equation, power supply voltage, the switching ratio in the switching transistor circuit, and the number of switchings. Using the expression, the voltage and current in the stepwise adiabatic charging method can be derived clearly. As a result, it is clarified analytically that, in N-step charging, the current is reduced to 1/N so that the energy dissipation is reduced to 1/N. Next, the experimental switching transistor circuit with the controller is described, which is composed of discrete ICs. The experimental inductor current in the circuit is investigated. The measured current is reduced to 1/N in N-step charging, which is consistent with the simulated one from the theory. It is also confirmed experimentally from the average power supply current that power consumption is reduced to 1/N.
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Todorovic, Andreja, Branimir Grgur, and Jelena Rajovic. "Influence of current and temperature on discharge characteristics of electrochemical nickel−cadmium system." Chemical Industry 64, no. 4 (2010): 319–35. http://dx.doi.org/10.2298/hemind100214015t.
Full textAbstract:
The paper elaborates determination of characteristic values in the discharging process of non-hermetic nickel-cadmium galvanic battery with nominal voltage Un = 60 V and nominal capacity qn = C5 = 190 Ah and its dependence from current and temperature. Study has been performed with the set of experimental metering of voltages, electromotive force, current from discharge time range and electromotive force in steady state regime before and after battery charging. Electromotive force characteristics are obtained by using the Nernst?s equation, while the least square method was used to determine the average values of internal electrical resistivity, power losses and efficiency level. These results were used in the approximate exponential functions to determine the range dependence of the efficiency level from the internal electrical resistance of discharge current in reliance from the temperature range. Obtained results show that, in accordance to the given voltage variation of 10% Un, this type of battery holds maximal full load current of one hour capacity at the temperature of 25?C and maximal full load current of two hours capacity at the temperature of ?30?C. The methodology used in the case study covers determination of the electromotive force in time range based on the metered results of values during complete battery fullness and emptiness with prior determination of equilibrium constants of galvanic battery reaction through method suggested by the author of this paper. Further process, using the electromotive force values obtained through the aforementioned process, the metered current, and approximate polynomial function of the nominal discharge voltage characteristic determines range of battery internal electric resistance from time, followed by the selection of discharge cases with average values for: voltage, electromotive force, internal electrical resistance, available and utilized power, power losses, and battery efficiency level. An overview of the obtained characteristics for analyzed battery and their comparison with the producers prescribed values and standards led to gaining of the valuable data that show how and in what measure do current and temperature influence the discharge characteristic of non-hermetic nickel-cadmium batteries with an especial observation of internal electrical resistance and battery efficiency level. Obtained results show that electrochemical power sources may provide electric energy with prescribed quality and quantity, with high level of work reliability, as well as with all other positive technical and economic effects within the given current-temperature range.
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Yang, Xiu Li, Tie Min Zhang, and Sheng Wen. "Study on the Output Characteristics of Piezoelectricity Generator." Advanced Materials Research 156-157 (October 2010): 908–14. http://dx.doi.org/10.4028/www.scientific.net/amr.156-157.908.
Full textAbstract:
. For the purpose of improving the output power of piezoelectricity generator (PG), this paper derivates the improving equivalent circuit of piezoelectricity element according to piezoelectricity effect. The dielectric loss and conductive loss are considered. The dielectric loss is caused by the hysteretic effect between leakage current and electric intensity in the medium inside. The conductive loss is caused by the ceramic particles boundary conditions. The relationship between output voltage and current is set up. The relationship between resistance and output power is set up. The relationship between output voltage and out power is set up. Those relationships are simulated and experimented. From the results, it is can be known that there is an optimum load(200 ) for the maximum output power (70 ) in condition of fixed structure, size and fixed excitation frequency and amplitude. With the increasing of voltage, the current is decreasing with parabolic form and the output power increases lowly to a maximum power firstly, and then decreases fast.
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Попов, Е. О., А. Г. Колосько, and С. В. Филиппов. "Проверка применимости закона полевой эмиссии к исследованию многоострийных полевых эмиттеров методом анализа степени предэкспоненциального множителя напряжения." Письма в журнал технической физики 45, no. 18 (2019): 13. http://dx.doi.org/10.21883/pjtf.2019.18.48230.17898.
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A method for testing the compliance of experimental current-voltage characteristics with a cold field emission mode is described. The method is based on the variation of voltage power-law exponent in the semilogarithmic coordinates ln (I/U^k) vs1/U, as well as the statistical analysis of experimental data fluctuations. It is shown that the current-voltage characteristics obtained using the high-voltage fast-scanning technique have a better fit to the field emission law than the characteristics given by a slow scanning with a constant voltage. A multi-tip nanocomposite emitter based on carbon nanotubes was taken as a sample. For processing experimental data, it was proposed to use modified Fowler-Nordheim coordinates with a voltage power-law exponent of 1.24.
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Kobayashi, Hiromichi, Natsuko Kuwako, Yoshihiro Okuno, and Shigeharu Kabashima. "Voltage-current characteristics of subsonic disk CCMHD generator." Electrical Engineering in Japan 130, no. 4 (March 2000): 58–65. http://dx.doi.org/10.1002/(sici)1520-6416(200003)130:4<58::aid-eej7>3.0.co;2-f.
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Luo, Xu, Fan Li, Li Fan, Tao Niu, Bo Li, Linxuan Tian, and Hongjie Yu. "Influence of Synchronous Condensers on Operation Characteristics of Double-Infeed LCC-HVDCs." Processes 9, no. 10 (September 23, 2021): 1704. http://dx.doi.org/10.3390/pr9101704.
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Considering the advantages that dynamic reactive power (var) equipment (such as synchronous condensers (SCs), which can control var independently and improve voltage stability), SCs are widely used in AC/DC hybrid power grid to provide emergency var and voltage support. In order to evaluate the dynamic var reserve capacity of SCs and analyze the influence of SCs on the operation characteristics of power system, a model with double-infeed line-commutated converter-based high-voltage direct currents (LCC-HVDCs) and SCs is established. Through theoretical derivation and PSCAD/EMTDC simulation, the effects of SCs on the operation characteristics of double-infeed LCC-HVDCs networks are studied. Then, the non-smooth voltage waveform of electromagnetic transient simulation is approximately transformed into smooth waveform by data fitting method. Finally, the processed voltage waveform is searched step by step to explore the boundary of voltage safety region to determine the dynamic var reserve capacity of SCs. The numerical results show that SCs can enlarge the voltage security region of the direct current (DC) subsystem, thus effectively improving the steady-state and transient security level of the double-infeed LCC-HVDCs networks.
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Dimitrov, Borislav, Khaled Hayatleh, Steve Barker, Gordana Collier, Suleiman Sharkh, and Andrew Cruden. "A Buck-Boost Transformerless DC–DC Converter Based on IGBT Modules for Fast Charge of Electric Vehicles." Electronics 9, no. 3 (February 28, 2020): 397. http://dx.doi.org/10.3390/electronics9030397.
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A transformer-less Buck-Boost direct current–direct current (DC–DC) converter in use for the fast charge of electric vehicles, based on powerful high-voltage isolated gate bipolar transistor (IGBT) modules is analyzed, designed and experimentally verified. The main advantages of this topology are: simple structure on the converter’s power stage; a wide range of the output voltage, capable of supporting contemporary vehicles’ on-board battery packs; efficiency; and power density accepted to be high enough for such a class of hard-switched converters. A precise estimation of the loss, dissipated in the converter’s basic modes of operation Buck, Boost, and Buck-Boost is presented. The analysis shows an approach of loss minimization, based on switching frequency reduction during the Buck-Boost operation mode. Such a technique guarantees stable thermal characteristics during the entire operation, i.e., battery charge cycle. As the Buck-Boost mode takes place when Buck and Boost modes cannot support the output voltage, operating as a combination of them, it can be considered as critically dependent on the characteristics of the semiconductors. With this, the necessary duty cycle and voltage range, determined with respect to the input-output voltages and power losses, require an additional study to be conducted. Additionally, the tolerance of the applied switching frequencies for the most versatile silicon-based powerful IGBT modules is analyzed and experimentally verified. Finally, several important characteristics, such as transients during switch-on and switch-off, IGBTs’ voltage tails, critical duty cycles, etc., are depicted experimentally with oscillograms, obtained by an experimental model.