Voltage Difference Research Articles

A New Model for Remote Calibration of Voltage Source Based on GPS Common-View Method

A remote calibration system of dc voltage source based on global positioning system (GPS) common-view method is proposed in this article. The system realizes remote calibration by installing the standard in the laboratory instead of the calibrated site and solves the problem of additional errors introduced by the standard at the calibrated site. By researching the relationship between voltage, frequency, and time, a new model for remote calibration of voltage source based on the GPS common-view method is built. The model reflects the mathematical relationship between calibration results and parameters measured by the calibration system. The accuracy of the model is a prerequisite to ensure the reasonableness of the calibration results of the entire calibration system. Based on the model, the voltage value of the standard side and the calibrated side can be compared remotely by measuring the time deviation between the pulse signal converted from voltage and the GPS synchronous clock signal. The voltage difference between the two sides is obtained and the remote calibration of dc voltage sources is implemented. By experiments, the voltage difference derived by the remote calibration model and measured by the traditional calibration method can be obtained when the calibration point is 0–1 V. The discrepancy between the results of the two methods is within <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.4244\times 10^{-5}$ </tex-math></inline-formula> V. The verification results of the two methods for the same dc voltage source are consistent in the evaluation of the accuracy level. It verifies the efficiency of the proposed system and the accuracy of the calibration model.

Research on SOC estimation of residual power of lithium-ion batteries for electric vehicles based on extended Kalman filtering algorithm

Abstract As the energy carrier of electric vehicles, how to accurately estimate the remaining power (SOC) of the battery is one of the key technologies in the field of electric vehicle design. Effective estimation of SOC can bring accurate continuous mileage information to the driver, theoretically avoid overcharging and discharging the battery, and also protect the driver's driving safety. In the research of SOC estimation method, constructing a suitable battery model is an important means to improve SOC estimation and to improve the prediction accuracy. In order to obtain a higher response accuracy of the model, this paper proposes an electric vehicle SOC model based on the extended Kalman filter algorithm. Based on the actual data of lithium-ion power battery, SOC estimation research is carried out. The research shows that: when the internal temperature of the battery is the same as the ambient temperature, and both are 25 °C, the model is accurate, the terminal voltage difference is small, and the average voltage difference is 9mV respectively; at room temperature, the extended Kalman filter algorithm has a significant effect on the recovery percentage of SOC voltage. The average is over 73%, and the accuracy is high. The extended Kalman algorithm in this paper we use to estimate the SOC current waveform. The simulation results show that the SOC discharge current is 4A, which has high estimation accuracy and strong applicability.

New Self-Isolated Wideband MIMO Antenna System for 5G mm-Wave Applications Using Slot Characteristics

This paper proposes a simple novel technique for self-isolating a MIMO antenna for mm-wave applications. MIMO antenna elements with inter-element separation of 0.2 mm ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.023\lambda $ </tex-math></inline-formula> at 35 GHz) and measured high isolation (>50 dB) are presented. By observing the concentration of surface waves on the radiating patch, several rigorously optimized slots of different shapes, positions, and dimensions are etched on the patch to enhance the inter-element isolation and increase the bandwidth within 28-37.5 GHz. The circuit models of the reference and proposed antennas have been presented. The coupling is measured by the level of the differences in the output voltage in both antennas. The novel mm-wave antenna exhibits high impedance bandwidth (>29%), high isolation (>50 dB), high efficiency (>90%), and low envelope correlation coefficient (< 0.005). Two configurations of MIMO antenna (i.e., <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 2$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 4$ </tex-math></inline-formula> ) are fabricated and measured to validate the simulation outcomes. The single reference antenna has dimensions of 10x12 mm 2 while the 1x2 array has dimensions of 19x12 mm 2. The presented design is the first to exhibit such wideband isolation improvement without any external decoupling structure at the mm-wave frequency range, to the best of the authors’ knowledge.

THE OUTPUT NOISE REDUCTION OF THE R-2R RESISTOR LADDER DIGITAL-ANALOG CONVERTER

A new method for reducing output noises in the R-2R resistor ladder digital-analog converter (DAC) is presented. The main reason for the output noises in R-2R resistor ladder DAC is the disadvantages and non-ideal features of the operational amplifier (Op-Amp). In case of the low numbers of the input combination there can be an output voltage without noises, because the voltage-error for the OpAmp in case of low output voltage is very small. But the low output voltage can be not the exact voltage because many times the 0 voltage on the negative input of the OpAmp forms is not clear. The high output voltage of the OpAmp can be more exact, but it will have noises because of the conflict between the voltage corresponding to the difference of the input voltages and the voltage corresponding to the current coming from the R-2R ladder. Using the new method, the output voltage of the R-2R resistor ladder DAC will be exactly in the full input combination range, and it will have almost no noise. In the primary 4-bit R-2R DAC designed in the 32 nm technology the INL (integral nonlinearity error) in case of 0000 input combination is 0.2 V, and the noise-error in case of 0101 input combination is 0.065 V. In the optimized R-2R DAC, the maximum INL error is 0.02 V at 0010 input combination and the maximum noise-error is 0.005 V at 0001 input combination. Using the method, the area of the circuit increases by 7%. As this disadvantage is very small the new approach is very preferable to use for accurate output signal in the R-2R resistor ladder DAC.

Variable Duty Control in Two-Mode LDC for Soft-Change at the Mode Transient

Two-mode low-voltage dc–dc converter (LDC) has been proposed for high and wide input voltage range in order to overcome the drawbacks of the conventional converters. With two operational modes, the two-mode LDC reduce the voltage stresses on the switches and dc offset current. However, it has large differences of capacitor voltage resulting in voltage spike on the switch at the mode transient. Moreover, the dc offset current has large variation between two modes. In this article, a variable control for two-mode LDC is proposed for changing the operational mode softly. The two mode LDC employing the proposed control is shown to minimize the difference of capacitor voltage and dc offset current over the entire input voltage range. The proposed control is verified by a 350–800 V input and 13.9 V/600 W output laboratory prototype.

Three-Phase Four-Wire Inverter for Grid Emulator Under Wide Inductance Variation to Evaluate the Performance of Distributed Generator

This paper presents a three-phase four-wire inverter to generate voltage sources under wide filter inductance variation. The voltage sources with distortion and unbalance are to emulate grid voltages. The distortion includes voltage sags, voltage swells, and harmonic components, and the unbalance includes voltage and phase-angle differences. With a conventional PI control and direct digital control (DDC) only, the voltage distortion cannot fulfill precisely because of the improper controls. While with the proposed modified direct digital control (MDDC) and harmonic-angle adjustment algorithm, the soft core saturation can be taken into account and the harmonic voltage distortion can be accurately emulated, respectively. Moreover, the proposed control scheme can achieve fast transient response. The control law is derived and the inverter with the control to generate grid voltage is described in detail. Simulated and experimental results from 10 kW prototype have verified the analyses and discussions

The traceability method of electronic transformer calibrators based on time series-weighted correlation degree extension integrating Hilbert phase-shift.

The traceability method directly affects the reliability and accuracy of the measurement of electronic transformers. The stability and unreliable traceability performance of analog devices would affect the traditional analog differential method. Thus, we propose a digital differential method combining a time series-weighted correlation degree extension integrating Hilbert phase-shift of four-term continuous third-derivative Nuttall window function, effectively suppressing the end effect problem and realizing the high-precision addition of the differential. Results of simulation experiments showed that the differential's deviation was <10-10, much less than that (1.32 × 10-4) due to the analog differential. The voltage and current ratio difference's combined standard uncertainty was 5.01 × 10-5 and 5.08 × 10-5, respectively, and 0.1718' in the phase error. Finally, an automatic traceability detection system was constructed. Compared with the traditional method, the accuracy and stability of the automatic system were better and could meet the traceability requirements for 0.05-accuracy electronic voltage transformer calibrator.

Моделирование и экспериментальное исследование четырехпроводной полосковой структуры с трехкратным модальным резервированием при отказах её элементов

The relevance of research on the rational use of redundancy by applying triple modal redundancy (MR) techniques to increase the resistance to ultra-wideband interference is highlighted. An experimental evaluation of the change in maximum voltage of decomposed pulses in a bilateral printed circuit board (PCB) with triple MR after failures has been performed. A special prototype of a double-sided PCB with triple MR with optimum parameters has been fabricated. SMD resistors were used as loads. At the far end of the redundant conductor of the PCB, a decomposition into 4 pulses at different input durations is shown. The maximum voltage changes before and after failures at input durations of 120 ps and 240 ps are 26.8% and 28%, respectively. The above comparison of the experimental and electrodynamic simulation results in the time and frequency domains showed their consistency. The maximum voltage and delay differences are 3.69 and 5.6 %, respectively.

Magnetic field improves ozone production in an atmospheric pressure surface dielectric barrier discharge: understanding the physico-chemical mechanism behind low energy consumption.

Herein, we studied the combined effects of the magnetic field and the alternating current driven air surface dielectric barrier discharge on ozone production, and found that a 0.13 T perpendicular magnetic field introduced into the discharge area significantly enhanced the ozone generation performance with a 36-108% increase in ozone number density and 24-80% increase in ozone yield depending on discharge voltage and frequency differences. To reveal the micro physico-chemical mechanism of the influence of a magnetic field and discharge parameters of discharge voltage and frequency on ozone generation, a plasma chemical reaction network involving electron collision-chain reactions was considered. The results show that these parameters jointly influence ozone generation by affecting electron collision reactions and chain chemical reactions by changing the mean electron energy and plasma gas temperature. In this study, both the experimental results and mechanism analysis suggested that an optimal discharge parameter for ozone generation is the magnetic field assisted, low frequency, high voltage (6.5 kHz, 6.5 kV) surface dielectric barrier discharge. These insights provide guidance for optimizing the discharge parameters of the magnetic field assisted discharge to increase ozone production and reduce energy consumption.

Research on Transfer Mechanism and Power Improvement Technology of the SCC-WPT System

Single capacitive coupled wireless power transfer (SCC-WPT) technology only needs one pair of metal plates for energy transmission. This provides a unique advantage in two-dimensional plane dynamic wireless power transfer. However, in practical application, this technology has a clear challenge in improving the transmission power ratings and efficiency. This article studies the power transfer mechanism of the SCC-WPT system based on stray capacitance and self-capacitance. A universal system model has been investigated, where the equivalent circuit model of the system is proposed. The two-port network of the coupler critical factors that limit the transmission power of the system has been analyzed. A new <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC–CL</i> compensation topology is proposed to achieve a phase difference of voltage between the primary side and secondary side to 90°, which improves the transmission power of the SCC-WPT system. In addition, the resonant operating condition of the system together with the efficiency is analyzed. Finally, an experimental prototype is built under the guidance of the analysis. Both simulation and experimental results verify the validity of the proposed model and the topology. The experimental results show that the prototype achieves 266 W output power with 62% dc–dc efficiency.

Design and analysis of Voltage Difference Transconductance Amplifier (VDTA) at FINFET CMOS technology

This paper proposes a FINFET (Fin Field Effect Transistor)-based Voltage Difference Transconductance Amplifier (VDTA). This paper aims to provide an amplifier that will enable VDTA to achieve its desired characteristics. The circuit proposed for FINFET-based VDTA operates with a bias current order of 150μA and a source voltage of 0.9V. The active element makes the amplitude electronically tuneable with bias current. The designed circuit was implemented in both GPDK 180nm technology and FINFET technology using the Cadence Virtuoso tool. Various factors, including technology node components and the operating voltage provided by FINFET VDTA structures, are compared. A Monte Carlo simulation is conducted for the suggested circuit, which dissipates 187.53μW of power. In comparison to the standard VDTA, it exhibits notably low power dissipation.

A New Electronic Tunable High-Frequency Meminductor Emulator Based on a Single VDTA

In this article, we have proposed an electronic tunable grounded meminductor emulator (MIE) using a single voltage difference transconductance amplifier (VDTA). Along with one VDTA, two MOSFETs and two capacitors are used in the proposed MIE. Overall, the proposed MIE requires only 18 MOS transistors and two grounded capacitors. The performance of the proposed MIE was validated using Cadence Virtuoso with a 180-nm CMOS library. The layout area of the emulator is only 1081 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> m <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{2}$</tex-math> </inline-formula> . The proposed design operates up to 25 MHz. To validate the theoretical and simulation results, an experiment was performed using CA3080 ICs and experimental results validate the simulated result. The power consumption of the proposed design is 5.93 mW.

Discharge and electromagnetic radiation behind the hole of simulated charging satellite surface under impact

To evaluate the threat of the impact of micrometeoroids and orbital debris on the satellite, we designed an unequal potential charging device on the satellite surface in the ground experiment. The unequal potential charging device is placed on a metal box to simulate the satellite shell. A small hole is opened on the metal box to study the coupling effect between the electromagnetic pulse generated by the impact and the small hole. We recorded the impact experiment's discharge current and voltage curves and detected the electromagnetic and plasma signals on both sides of the hole. The experimental results show that the plasma entering the metal box through the small hole will release the voltage difference inside and outside the metal box and cause the discharge. The electromagnetic field probe in the metal box also detected the electromagnetic radiation signal of 20∼100 MHz.

RESEARCH WORK OF RESOURCE FOR USING STRAIN GAGE TO DO CUTTING FORCE MEASURING TOOL

Some measuring tools such as pressure gauges, weight gauges, and the grave of pressure gauges were made by using a Strain gage. Based on the principle of these measuring tools Strain gage is required to carry out the force of the lathe machine. That experiment is determined the power of measuring equipment how to increase electromagnetic current, voltage difference, and the magnitude of the resistance, depending on the relative dimension of the compressive strength of the material, and the relative displacement of the material compares to the change in resistance.

Effects of voltage variation on heat and stress distributions in the electrochromic glass

Electrochromic glass has been used in many applications, such as the building envelope, because its light filtration can be adjusted in a controllable manner using low input energy. Electrochromic glass is a composite glass that consists of five layers. These five layers have two layers of glass, two layers of Indium Tin Oxide (ITO) and a layer of Poly (3-hexylthiophene), which is an electrochromic film. When a current passes through the glass, a voltage difference occurs, resulting in a redox reaction at an electrode layer. This causes the glass to change colour from transparent to opaque, resulting in a change in radiation absorption, which affects the heat transfer process. The study investigates temperature and thermal stress distributions in electrochromic glass by adjusting an input voltage in a range of 0–2.6 V. The spectral absorbance data at all light spectrum ranges were experimentally obtained. The averaged absorbance data were used for calculating the heat generation rate, and used as the input parameter for three-dimensional (3D) multiphysics simulations. The maximum temperature and thermal stress of the electrochromic glass are reached at 1.8 V according to the high rate of heat generation. The peak value of stress occurs at the interface between ITO and electrochromic layers. This study provides information regarding the heat transfer process and the stress induced in the electrochromic glass which varies with the applied voltages and can be applied to glass industries and many other related fields.

Outcomes and atrial substrate analysis in patients with HIV undergoing atrial fibrillation ablation.

Patients with HIV infection have increased risk of atrial fibrillation, but the pathophysiologic mechanisms and the utility of catheter ablation in this population are not well-studied. We aimed to characterize outcomes of atrial fibrillation ablation and left atrial substrate in patients with HIV. The study was a retrospective propensity score-matched analysis of patients with and without HIV undergoing atrial fibrillation ablation. A search was performed in the electronic medical record for all patients with HIV who received initial atrial fibrillation ablation from 2011 to 2020. After calculating propensity scores for HIV, matching was performed with patients without HIV by using nearest-neighbor matching without replacement in a 1:2 ratio. The primary outcome was freedom from atrial arrhythmia and secondary outcomes were freedom from atrial fibrillation, freedom from atrial tachycardia, and freedom from repeat ablation, compared by log-rank analysis. The procedures of patients with HIV who underwent repeat ablation at our institution were further analyzed for etiology of recurrence. To further characterize the left atrial substrate, a subsequent case-control analysis was then performed for a set of randomly chosen 10 patients with HIV matched with 10 without HIV to compare minimum and maximum voltage at nine pre-specified regions of the left atrium. Twenty-seven patients with HIV were identified. All were prescribed antiretroviral therapy at time of ablation. These patients were matched with 54 patients without HIV by propensity score. 86.4% of patients with HIV and 76.9% of controls were free of atrial fibrillation or atrial tachycardia at 1 year (p = .509). Log-rank analysis showed no difference in freedom from atrial arrhythmia (pvalue .971), atrial fibrillation (p-value .346), atrial tachycardia (pvalue .306), or repeat ablation (pvalue .401) after initial atrial fibrillation ablation in patients with HIV compared to patients without HIV. In patients with HIV with recurrent atrial fibrillation, the majority had pulmonary vein reconnection (67%). There were no significant differences in minimum or maximum voltage at any of the nine left atrial regions between the matched patients with and without HIV. Ablation to treat atrial fibrillation in patients with HIV, but without overt AIDS is frequently successful therapy. The majority of patients with recurrence of atrial fibrillation had pulmonary vein reconnection, suggesting infrequent nonpulmonary vein substrate. In this population, the left atrial voltage in patients with HIV is similar to that of patients without HIV. These findings suggest that the pulmonary veins remain a critical component to the initiation and maintenance of atrial fibrillation in patients with HIV.

A novel-16–60 V input common-mode voltage current-shunt monitor

This paper presents an effective design solution for current-shunt monitor (CSM) adapting to both positive and negative power supply applications, where the supply voltage is input common-mode voltage (CMV) of CSM ranged from −16 to 60 V. The proposed CSM mainly consists of a high-voltage low-drop output (HVLDO) regulator, a CSM core, and a 2nd-stage gain generator. The HVLDO regulator converts the independent supply voltage (5-16 V) to a stable internal output supply voltage of 5 V for other consequent circuits. The proposed CSM core adopts a fully-differential amplifier, a single-ended output amplifier, current-mirror transistors, and several resistors to constitute a stable negative feedback system. Due to its stable operation, the CSM core with both positive and negative CMV can successfully detect drops across the shunt resistor. The 2nd-stage generator is used to achieve a higher gain. By selecting proper transistor and resistor size in both CSM core and 2nd-stage gain generator, a total scaled gain of 100 V/V is achieved in this study. The proposed CSM architecture has been successfully implemented in a 0.25μm Bipolar-CMOS-DMOS (BCD) technology, and the area is around 1.44 mm2. Measurements show that the proposed CSM with an input CM voltage ranged from -16–60 V can sense an input voltage difference 4–16 mV.

Investigation into accuracy of turn-to-turn contact resistance measurement in low-frequency AC method by 3D numerical simulation

In this paper, we discuss two points: (a) the accuracy of contact resistance measurement using the low-frequency AC (LFAC) method and (b) the relation between the contact resistance and the contact resistivity. The LFAC method is used to measure the turn-to-turn contact resistance of a no-insulation (NI) rare-earth barium copper oxide (REBCO) pancake coil. We have previously shown the validity of the LFAC method by experiment. In this paper, the current distribution of aNI REBCO pancake coil on the applyication of the LFAC method is investigated using numerical simulation. The simulation results show the possibility of improving the measurement accuracy. Hence, a correction method is also proposed using the phase difference of the coil voltage and current. The LFAC simulation results also indicate the inconsistency of the well-known relation between contact resistance and contact resistivity. Therefore, we investigated the relation through the LFAC and sudden-discharging test simulations.

Numerical study of a 20-cell tubular segmented-in-series solid oxide fuel cell

Tubular segmented-in-series solid oxide fuel cells (SIS–SOFCs) have the advantages of good thermal shock resistance, mechanical strength, and easy sealing because of their tubular structures, and they gain a high operating voltage due to their series configuration. Previous studies have mainly focused on the optimization of a single cell segment while ignoring the flow and heat transfer between series cells. In this study, a 20-cell in-series SOFC model is developed by coupling the electrochemical reactions and mass, momentum, and heat transfer processes. The temperature and composition have a striped distribution because of the noncontinuous electrochemical reaction area. The discontinuity of the heat generation and the intrinsic limit of the access air cooling lead to temperature nonuniformity, while the uneven temperature and component consumption result in the nonuniform voltage of each series cell. For the problems of nonuniform temperature and voltage distributions in the SIS–SOFC, two effective solutions are proposed and evaluated. By introducing a heat pipe as a fuel inlet tube and increasing the length of the downstream cell in turn, the temperature difference is reduced from 111 K to 25 K, and the voltage difference is decreased from 120 mV to 7 mV at an operating current of 3 A.

A Method for Leakage Current and Power Reduction of Buffer in 65-nm CMOS Technology Based on the Pileup-Effect

In small-size Complementary Metal Oxide Semiconductor (CMOS) technology, the size of Very Large-Scale Integration (VLSI) below 90nm becomes higher and higher due to the enhancement of the short channel effect of transistors. CMOS Buffer is a very common circuit unit in VLSI. In this paper, a Pileup effect transistor (PET) is proposed to reduce the subthreshold leakage current of the CMOS buffer. The main principle of PET technology is to reduce the voltage difference between gate and source and the voltage difference between drain and source by lowering the voltage of source so as to reduce the subthreshold leakage current. Through simulation-based on Cadence and Taiwan Semiconductor Manufacturing Company (TSMC) N65 library, PET technology can reduce leakage current power consumption by about one-twelfth of the original while maintaining the function of the original CMOS buffer. PET technology has also been found to reduce current consumption in the transition state by about 40%.