Voltage Difference Research Articles

Comparison of Multi-step Prediction Models for Voltage Difference of Energy Storage Battery Pack Based on Unified Computing Operation Platform

Comparison of Multi-step Prediction Models for Voltage Difference of Energy Storage Battery Pack Based on Unified Computing Operation Platform

Selectively nucleotide‐derived RuP on N,P‐codoped carbon with engineered mesopores for energy‐efficient hydrogen production assisted by hydrazine oxidation

AbstractIntegrating hydrogen evolution reaction (HER) with hydrazine oxidation reaction (HzOR) has an encouraging prospect for the energy‐saving hydrogen production, demanding the high‐performance bifunctional HER/HzOR electrocatalyst. Ruthenium phosphide/doped carbon composites have exhibited superior activity toward multiple electrocatalytic reactions. To explore the decent water‐soluble precursors containing both N and P elements is highly attractive to facilely prepare metal phosphide/doped carbon composites. Herein, as one kind ecofriendly biomolecules, adenine nucleotide was first employed to selectively fabricate the highly pure RuP nanoparticles embedded into porous N,P‐codoped carbons (RuP/PNPC) with a straightforward “mix‐and‐pyrolyze” approach. The newly prepared RuP/PNPC only requires 4.0 and −83.0 mV at 10 mA/cm2 separately in alkaline HER and HzOR, outperforming most of reported electrocatalysts, together with the outstanding neutral bifunctional performance. Furthermore, the two‐electrode alkaline and neutral overall hydrazine splitting both exhibit significant power‐efficiency superiority to the corresponding overall water splitting with the voltage difference of larger than 2 V, which can be also easily driven by the fuel cells and solar cells with considerable H2 generation. Our report innovates the N‐ and P‐bearing adenine nucleotide to effortlessly synthesize the high‐quality RuP/doped carbon composite catalysts, highly potential as a universal platform for metal phosphide‐related functional materials.

Enabling the wide memory window and long endurance in hafnia-based FeFET from the perspective of interfacial layer

In this research, we employed AlOx and AlON thin films as interfacial layers (IL) in ferroelectric capacitors to achieve a significantly large memory window (MW) of 4.5 V and endurance up to 108 cycles. By manipulating the IL materials, we obtain different intensity of voltage drop across the IL, thus changes the depolarization field in HZO, leading to increased MW. Furthermore, we integrated AlO x /AlON into ferroelectric FETs and confirmed that AlO x /AlON indeed enhances the threshold voltage difference (∆V T ), while maintaining an endurance of 109 cycles. this study shed light on design guidelines for large MW memory devices.

Real-time signal processing and data acquisition for the Electric Field Detector (EFD-02) on the CSES-02 satellite

The Electric Field Detector (EFD-02) on board the second China Seismo-Electromagnetic Satellite (CSES-02) will measure the electric field components at a Low Earth Orbit (LEO) over a wide frequency band (DC – 3.5 MHz) and with 1 μV/m sensitivity in the Low Frequency band. EFD-02 will measure the voltage differences between pairs of probes installed at the tips of four booms deployed from the satellite. In this article, we describe the Zynq System on Chip (SoC)-based digital hardware subsystem dedicated to signal processing, and the selected implementation strategy, which successfully complied to the specific requirements of the space mission. Furthermore, we present a comprehensive overview of the assessed instrument performance.

Delta-T Flicker Noise Demonstrated with Molecular Junctions.

Electronic flicker noise is recognized as the most abundant noise in electronic conductors, either as an unwanted contribution or as a source of information on electron transport mechanisms and material properties. This noise is typically observed when a voltage difference is applied across a conductor or current is flowing through it. Here, we identify an unknown type of electronic flicker noise that is found when a temperature difference is applied across a nanoscale conductor in the absence of a net charge current or voltage bias. The revealed delta-T flicker noise is demonstrated in molecular junctions and characterized using quantum transport theory. This noise is expected to arise in nanoscale electronic conductors subjected to unintentional temperature gradients, where it can be a performance-limiting factor. On the positive side, delta-T flicker noise can detect temperature differences across a large variety of nanoscale conductors, down to atomic-scale junctions with no special setup requirements.

Charging and discharging a supercapacitor in molecular simulations.

As the world moves more toward unpredictable renewable energy sources, better energy storage devices are required. Supercapacitors are a promising technology to meet the demand for short-term, high-power energy storage. Clearly, understanding their charging and discharging behaviors is essential to improving the technology. Molecular Dynamics (MD) simulations provide microscopic insights into the complex interplay between the dynamics of the ions in the electrolyte and the evolution of the charge distributions on the electrodes. Traditional MD simulations of (dis)charging supercapacitors impose a pre-determined evolving voltage difference between the electrodes, using the Constant Potential Method (CPM). Here, we present an alternative method that explicitly simulates the charge flow to and from the electrodes. For a disconnected capacitor, i.e., an open circuit, the charges are allowed to redistribute within each electrode while the sum charges on both electrodes remain constant. We demonstrate, for a model capacitor containing an aqueous salt solution, that this method recovers the charge-potential curve of CPM simulations. The equilibrium voltage fluctuations are related to the differential capacitance. We next simulate a closed circuit by introducing equations of motion for the sum charges, by explicitly accounting for the external circuit element(s). Charging and discharging of the model supercapacitor via a resistance proceed by double exponential processes, supplementing the usual time scale set by the electrolyte dynamics with a novel time scale set by the external circuit. Finally, we propose a simple equivalent circuit that reproduces the main characteristics of this supercapacitor.

DTMOS based four-quadrant multiplier/divider with voltage difference transconductance amplifier

DTMOS based four-quadrant multiplier/divider with voltage difference transconductance amplifier

Optimizing fault diagnosis for electric vehicle battery systems: Improved Giza pyramids construction and advanced gradient boosting decision trees

This manuscript proposes an online multi-fault diagnostic technique for the series string batteries in electric vehicles to identify and diagnose external/internal short circuits, sensor faults, and connection fault detection. The proposed technique combines the Improved Giza Pyramids Construction and Gradient Boosting Decision Trees. Many variables, including road conditions, electromagnetic interference, and driving habits, may complicate the battery fault system, multi-parameter or non-linear coupling, making it challenging to diagnose faults properly by using a single parameter in the real operation of an electric vehicle. The voltage fluctuation data is collected by simulating a battery discharging and charging investigation in a vibration setting. By deconstructing and rebuilding the discrete wavelet transform, the proposed approach removes voltage signal noise. To categorize the fault state, the voltage change, co-variance and variance matrixes, and voltage characteristics are employed as input-values in the improved Giza pyramids construction, and gradient boosting decision trees technique. The Improved Giza pyramids construction technique is utilized to detect fault signals and determine the degree of the defect. The cell faults are separated from other faults using the Gradient Boosting Decision Trees approach by identifying the surrounding voltages with fault flags. Furthermore, the correlation coefficient of the nearby voltage difference and current isolates connection and voltage sensor defects. The multi-fault diagnosis approach may prevent erroneous fault detection and offer high resilience to battery inconsistencies and normal measurement errors of state of health, ambient temperature, and state of charge. The projected control theme is evaluated on the MATLAB platform and its performance is assessed. The performances of the proposed method are compared with existing techniques like Artificial Bee Colony, Differential Evolution, Improved Giza Pyramids Construction and Particle Swarm Optimization. The efficiency of the Artificial Bee Colony, Differential Evolution, Particle Swarm Optimization, and Improved Giza Pyramids Construction and proposed technique is 82.237 %, 79.265 %, 87.1029 %, 89.023 % and 95.4501 %.

An Electrical Resistance Diagnostic for Conductivity Monitoring in Laser Powder Bed Fusion.

With the growing interest in metal additive manufacturing using laser powder bed fusion (LPBF), there is a need for advanced in-situ nondestructive evaluation (NDE) methods that can dynamically monitor manufacturing process-related variations, that can be used as a feedback mechanism to further improve the manufacturing process, leading to parts with improved microstructural properties and mechanical properties. Current NDE techniques either lack sensitivity beyond build layer, are costly or time-consuming, or are not compatible for in-situ integration. In this research, we develop an electrical resistance diagnostic for in-situ monitoring of powder fused regions during laser powder bed fusion printing. The technique relies on injecting current into the build plate and detecting voltage differences from conductive variations during printing using a simple, cheap four-point electrode array directly connected to the build plate. A computational model will be utilized to determine sensitivities of the approach, and preliminary experiments will be performed during the printing process to test the overall approach.

Progress on Bifunctional Carbon‐Based Electrocatalysts for Rechargeable Zinc–Air Batteries Based on Voltage Difference Performance

AbstractZinc–air batteries (ZABs) hold potential as clean, cost‐effective, and sustainable energy storage system for the next generation. However, the application of ZABs remains challenging because of their poor rechargeability and low efficiency . The design of efficient bifunctional catalysts toward oxygen reduction reaction (ORR) during discharging and the oxygen evolution reaction (OER) during charging is essential to developing rechargeable ZABs. Transition metal (TM)‐doped carbon (TM‐C) materials stand out from all the available bifunctional catalysts due to the excellent specific surface area, diverse morphological structures , and the multiple metal active sites formed after TM doping. This paper, therefore, focuses on the synthesis, electrochemical properties, and potential mechanism of TM‐C catalysts. To make a novelty and logical statement, the voltage difference (ΔE = Ei = 10 − E1/2) between the ORR/OER catalytic process is employed to categorize different TM‐C catalysts reported in recent years, which are divided into two groups: I (ΔE = 0.7 − 0.9 V) and II (ΔE = 0.5 − 0.7 V). The catalytic mechanisms of bifunctional catalysts are clarified. More ways and ideas for synthesizing high‐performance bifunctional TM‐C catalysts are also provided. Finally, the current problem and prospects of this group materials are presented.

An improved online minor turn-turn winding fault diagnosis in a single-phase transformer based on instantaneous induced voltages and primary current locus

Online detection of the minor turn-turn winding fault in a single-phase transformer under no load condition using current waveform analysis is very complicated. In this paper, a new online minor turn-turn winding fault diagnosis in a single-phase transformer is proposed. Using a correlation between the instantaneous primary and secondary induced voltages difference with the primary current as a geometry location, the minor winding faults is detected effectively. The healthy transformer locus is considered as a reference locus. The minor winding faults could be detected by graphical analysis of the faulty loci with the reference locus in every cycle. Incipient winding fault detection in a single-phase transformer using the proposed technique under no load condition is a significant of this paper. The proposed locus is changed in shape and dimension by the winding faults severity. Therefore, the minor winding faults severity determination is carried out by faulty locus area comparison with the healthy locus. The experimental results validate the simulation results completely.

Measurement and simulation of voltage differences under ribs and channels and temperature variations within channels in PEMEC

The internal voltage inhomogeneity in a proton exchange membrane electrolyzer cell (PEMEC) is experimentally investigated by using customized gaskets. Three miniature thermocouples are strategically placed inside the channels, specifically in the inlet region, middle region, and outlet region, to monitor temperature variations along the channels. Local voltage measurements are conducted in 13 regions corresponding to the flow channels and 12 regions corresponding to the ribs, under various operating conditions. Additionally, a three-dimensional simulation is performed to analyze the underlying causes of non-uniform voltage distribution and temperature variation. The results reveal contrasting trends in temperature changes along the flow direction, attributable to the varying magnitudes of heat loss and electrochemical heat at different current densities. At low current densities, temperatures increase from the inlet to the outlet along the channels, while at high current densities, temperatures decrease in the same direction. Furthermore, the local voltages of the flow channels (Vchan) and the ribs (Vrib) exhibit different increases along the flow direction at various current densities with the Vchan consistently smaller than Vrib. The inhomogeneity of Vchan is found to be greater than that of Vrib due to bubble disturbances in the channels. The proposed measurement principle for local voltage distribution in PEMECs provides insights into the performance discrepancies between the channel and rib scales in the flow field, thereby enhancing our understanding of electrical property inhomogeneity within the cell.

Dynamic Li+ Capture through Ligand-Chain Interaction for the Regeneration of Depleted LiFePO4 Cathode.

After application in electric vehicles, spent LiFePO4 (LFP) batteries are typically decommissioned. Traditional recycling methods face economic and environmental constraints. Therefore, direct regeneration has emerged as a promising alternative. However, irreversible phase changes can significantly hinder the efficiency of the regeneration process owing to structural degradation. Moreover, improper storage and treatment practices can lead to metamorphism, further complicating the regeneration process. In this study, a sustainable recovery method is proposed for the electrochemical repair of LFP batteries. A ligand-chain Zn-complex (ZnDEA) is utilized as a structural regulator, with its ─NH─ group alternatingly facilitating the binding of preferential transition metal ions (Fe3+ during charging and Zn2+ during discharging). This dynamic coordination ability helps to modulate volume changes within the recovered LFP framework. Consequently, the recovered LFP framework can store more Li-ions, enhance phase transition reversibility between LFP and FePO4 (FP), modify the initial Coulombic efficiency, and reduce polarization voltage differences. The recovered LFP cells exhibit excellent capacity retention of 96.30% after 1500 cycles at 2C. The ligand chain repair mechanism promotes structural evolution to facilitate ion migration, providing valuable insights into the targeted ion compensation for environmentally friendly recycling in practical applications.

Compositional influence of CuAlMn SMA coated optical fiber towards sensing low temperature

Low temperature sensing with currently available sensors is a challenging task due to the several limitations in usage under harsh environmental conditions. Hence, optical fiber-based sensors could be a better alternative for sensing and monitoring applications due to their immunity at extreme temperatures (both Cryogenic and high temperature), pressure, electromagnetic interference, and power fluctuations. Moreover, the sensing properties are further improved by applying metal coating on optical fiber. In this respect, Shape Memory Alloy (SMA) coating on optical fiber shows enhanced sensitivity due to its unique property of shape memory effect. Particularly, copper-based SMAs are investigated in this regard because of their solid-state actuation characteristics at extreme temperature conditions. Hence, we have coated the optical fiber with CuAlMn SMA by thermal evaporation technique. We have varied the composition of SMA to control the transformation temperature (TT) at low-temperature regions. In the CuAlMn system, TTs are highly dependent on the concentrations of Al and Mn content. We have varied the weight percentages of Al and Mn present in CuAlMn SMA, to achieve the actuation at sub-zero temperature. We have used 2 different wire compositions (Cu-9Al-12.6Mn, and Cu-8.8Al-12.2Mn) for the preparation of the CuAlMn SMA thin films. The film obtained using the Cu-9Al-12.6Mn wires, has shown the lowest transformation temperature and maximum actuation/ displacement (∼10 mm) at low temperature (liquid N2) region. Such actuation of SMA-coated fiber results in significant optical signal attenuation (∼ 8 V peak-to-peak voltage difference under liquid N2 exposure) at the detector end. Thus, we can claim that the CuAlMn-coated optical fiber can be used as a cryogenic sensor due to its significant optical signal attenuation.

Voltage, power, and energy production of a Shewanella oneidensis biofilm microbial fuel cell in microgravity

Future long-term space travel requires both efficient waste management and renewable energy production to be feasible. One such option in addressing these issues is a microbial fuel cell (MFC) that converts chemical energy in organic matter to electrical energy through biological processes of microbes. Electroactive biofilms are special colonies of microbes that utilize an extracellular matrix to increase the endurance and growth of bacterial colonies through the sharing of resources and the depositing of electrons. We studied the power production of a biofilm MFC by testing the fuel cell in microgravity over time on the International Space Station (ISS). We utilized Shewanella oneidensis, an established electroactive biofilm, to break down a nutrient solution and release electrons and protons, producing a voltage difference across the cell. The S. onedensis biofilm grew more prolifically under low-pressure conditions, making it well suited for microgravity; consequently, the consumption of sodium lactate in a larger biofilm caused an increase in anaerobic respiration of the bacteria. This increased the voltage difference recorded across the cell and the corresponding power of the MFC. Our results are consistent with our hypothesis that there would be an increase in voltage and power production over time; however, an insufficient amount of growth medium eventually led to a decrease in voltage and power production as the biofilm died out. Power output during microgravity testing increased over time, coinciding with nutrient solution pump cycles. This experiment established that an MFC is a promising avenue for the development of renewable energy in microgravity.

A Novel Isolated Gate Driver Power Supply Method for Self-Powered SiC DC Solid-State Switch Using Thermoelectric Generation

DC switches using power electronics technology are increasingly used in dc power systems. Unlike other typical power electronic equipment, it is difficult for the DC switch to acquire energy from the primary circuit in the long-term closure state without d <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</i> /d <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</i> or potential difference. As a result, the gate drivers of the devices in DC switches can only be powered from the ground via a complicated and expensive secondary isolation power supply system. This paper proposes a novel isolated gate driver power supply method based on thermoelectric generation for SiC DC switches. By utilizing the unique high operating temperature of wide-bandgap devices, self-power generation can be achieved through the temperature difference between the device and the environment even without d <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</i> /d <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</i> or voltage difference. Following the comprehensive integration of the thermoelectric generator and the radiator, a 1.7kV/400A DC switch prototype capable of long-term steady self-power supply is developed, proving the efficacy of the proposed method.

An efficient high-gain bidirectional interleaved boost converter for PV integration to DC microgrid.

The design of a power electronic interface for high voltage difference DC buses is a key aspect in DC microgrid applications. A multi-port non isolated interleaved high-voltage gain bidirectional converter, which facilitates bidirectional power transfer and islanded operation in a DC microgrid, is presented in this paper. The forward high-voltage transfer ratio is achieved using a voltage multiplier circuit, and the high-gain step-down power conversion is performed using a resonant power module. A novel power transfer selection algorithm is proposed to control power flow among the interfaces of the RES, ESS, and DC grid converters, which utilizes the net power difference as the basis for switching the converter. The proposed converter is simulated for a 24 V PV source, 12 V battery, and 400 V DC grid interface using MATLAB/SIMULINK. A 200 W hardware prototype is implemented. The simulation results for voltages, currents, and power flow among RES, ESS, and microgrid DC bus proved an excellent voltage regulation, efficient power conversion, and a feasible duty cycle range with high voltage gain. These observations are validated through equivalent experimental results. A comparison is made regarding achieved gain, component sizing, achievable power transfer modes, efficiency, and control complexity with existing converters for DC microgrid applications. The presented topology proved to be a better interface with multiple-mode support with high efficiency.

Toroidal seawater conductivity sensors and instrumentation for anti-submarine warfare

This paper describes the development of toroid-based seawater conductivity sensors and instrumentation for 0 to 60 mS/cm conductivity range and 50 bar hydrostatic pressure operational capability which is equivalent to 500 metres of ocean depth. Double core toroidal transformer concept was used and investigated for Mn-Zn and Fe based nanocrystalline cores, turns ratio and temperature dependence. Different excitation and sense coil turn numbers were fabricated by keeping the turn&#x2019;s ratio 1:2, 1:4, 1:6 and 1:8. Optimum frequency of Mn-Zn based conductivity sensors with lower and higher turn numbers were observed for turn ratio 1:8 and 1:4 respectively at 120 kHz and obtained voltage responses of 952 and 1567 mV. Fe based Nano crystalline core with turn ratio 1:8 shows an optimum frequency of 70 kHz and giving a voltage difference of 830 mV. Two dimensional polynomials of order 2 were presented for temperature dependence of conductivity for Mn-Zn core based sensors. Sensor responses of Fe based nanocrystalline core sensors in &#x2018;lower turn number&#x2019; configuration with same turn ratio is presented and observed linear temperature dependence compared to Mn-Zn based sensors. The mechanical design and frequency of operation of developed conductivity sensors gives inherent immunity to ASW band of frequency interference. The efficacy of conductivity sensor with measuring electronics and commercial standard sensors profiling was proved experimentally compared up to 500 metres in sea profiling and obtained a root mean square error of 0.42 for profile data.

Durable bifunctional electrocatalyst for cathode of zinc-air battery: surface pre-reconstruction of La0.7Sr0.3MnO3 perovskite by iron ions

The utilization of manganese-based perovskite in rechargeable Zn-air batteries encounters challenges related to low catalytic activity and inadequate stability. In this study, we have employed a surface pre-reconstruction technique to produce La0.7Sr0.3MnO3 nanoparticles adorned with iron ions (LSM/Fe-1.5). The optimized LSM/Fe-1.5 catalyst demonstrates an increase in ORR and OER intrinsic activities by 1.8 and 4.9 times, respectively, exhibiting ORR/OER bifunctional activity comparable to that of commercial Pt/C and RuO2. The Zn-air battery employing the LSM/Fe-1.5 catalyst exhibits a charge-discharge voltage difference of 0.89 V after 1500 cycles (500 h). The improved activity of ORR can be attributed to the selective dissolution of A-site cations, optimization of B-site electronic structure and oxygen vacancy concentration. The enhanced OER activity can be ascribed to the augmentation of adsorption energy of iron ions on the surface of perovskite, along with the synergistic influence of iron ions and surface oxygen vacancies. This study not only presents an effective approach for developing efficient and durable bifunctional catalysts for broader application in Zn-air batteries, but also broadens the influence of iron ions in the OER process to include manganese-based perovskite oxide.

Investigation of a Low-Speed Commutation Voltage Shock Problem in Three-Level ANPC Inverter with Hybrid Modulation Mode

With the development of the photovoltaic industry; there will be an increasing demand for efficient, high-power density, and low-cost grid interface converters. Compared with two-level inverters, multilevel inverters have the following advantages: (1) lower device voltage ratings; (2) better output filtering spectrum; (3) lower electromagnetic interference (EMI) noise; and (4) higher switching speed capability. However, the complex switching circuit of the multilevel inverter will bring more parasitic inductance, resulting in severe switching overvoltage (ringing). Especially in order to reduce the cost of the inverter, using the long-loop modulation mode, the commutation loop will introduce more parasitic inductance, which will make the overvoltage more serious. Consider that commonly used overvoltage absorption schemes are effective only for overvoltage or suppression of oscillations. Therefore, a new overvoltage absorption circuit is proposed in this paper, which can not only alleviate the overvoltage and ringing phenomena but also suppress the effect of voltage jumps during low-frequency switching on high-frequency input voltage. This overvoltage absorption circuit is characterized by low overvoltage, fast ringing damping, and minimum capacitance. Experiments and simulations are conducted to verify the effectiveness of this overvoltage absorption circuit using a three-level ANPC inverter as a prototype. The results show that the proposed overvoltage absorption circuit can significantly reduce the overvoltage level, shorten the oscillation time, and reduce the voltage difference between the upper and lower DC bus capacitors.