Types Of Conductors Research Articles

Activating Reversible V4+/V5+ Redox Couple in NASICON-Type Phosphate Cathodes by High Entropy Substitution for Sodium-Ion Batteries.

Vanadium-based Na superionic conductor (NASICON) type materials (NaxVM(PO4)3, M = transition metals) have attracted extensive attention when used as sodium-ion batteries (SIBs) cathodes due to their stable structures and large Na+ diffusion channels. However, the materials have poor electrical conductivity and mediocre energy density, which hinder their practical applications. Activating the V4+/V5+ redox couple (V4+/V5+≈4.1 V vs Na+/Na) is an effective way to elevate the energy density of SIBs, whereas the irreversible phase transition of V4+/V5+ and severe structural distortion will inevitably result in fast capacity fading and unsatisfactory rate capability. Herein, a high entropy regulation strategy is proposed to optimize the detailed crystal structure and improve the reversibility of crystalline phase transformation and electrical conductivity of the material. With the activated reversible V4+/V5+ redox couple, stable structure, and fast electrochemical kinetics, the high entropy material Na3.2V1.5Fe0.1Al0.1Cr0.1Mn0.1Cu0.1(PO4)3 (NVMP-HE) exhibits an outstanding electrochemical performance with highly reversible specific capacity of 120.1 mAh g-1 at 0.1 C and excellent cycling stability (92.4% retention after 1000 cycles at 20 C). Besides, the in situ X-ray diffraction (XRD) measurement reveals that a smooth three-phase transition reaction is involved in this high-entropy cathode and the existence of mesophase facilitates a fast phase transition.

A Study on the Evaluation Method for the Operating Status of Overhead Transmission Lines Based on Analytic Hierarchy Process (AHP)

ABSTRACTTo address the challenge of dynamically assessing overhead transmission lines under varying meteorological conditions through manual inspections and drone monitoring, this study proposes an evaluation method for the operating status of overhead transmission lines based on the Analytic Hierarchy Process (AHP). A mathematical model based on AHP is first established to perform weighted processing of five meteorological factors, generating a comprehensive meteorological dataset. A simulation model for the LGJ‐300/70 type conductor is then developed under the temperature field, where temperature distribution during operation is determined based on different meteorological data. Stress variations are observed, and evaluation criteria are established by calculating displacement deviations in the two‐dimensional transmission line model. The transmission line is considered to be in a normal operating state when the maximum displacement deviation is ≤ ±0.63 mm. This demonstrates that the AHP‐based evaluation method can effectively enable dynamic assessment of the operating status of overhead transmission lines.

Power Transmission Technology Using Wireless Network

In this paper, we have presented the concept of wireless transmission i.e. power transmission without using any type of the electrical conductor and/or wires. We have presented an idea that is discussed here about how electrical energy can be transmitted as microwaves so that to reduce the transmission, allocation and other types of losses. Such technique is known as Microwave Power Transmission (MPT). We have also presented and correlated several aspects with the currently available Power transmission systems to the related history of wireless power transmission systems and also the related developmental changes. The basic design, merits and demerits, applications of Wireless Power Transmission are also discussed . The paper describes the various types of WPT technologies; Inductive Coupling, Magnetic Resonance and Radio Frequency (RF) technology. It also discusses the advantages and shortfalls of each type. An extensive survey of past works was discussed. Results from the research findings showed that distance and conversion efficiency were limiting factors in implementing wireless transfer technology

Colloidal route towards sodium ionic conductor (NASICON) 3D complex solid electrolyte structures fabricated by Direct Ink Writing (DIW)

Progressing towards a sustainable energy model, safer new generation high-performance energy storage devices with large energy density and power are needed. In this sense, the improvement in terms of efficiency and sustainability has led to the interest in solid-state batteries (SSBs). Lately, sodium-ion batteries (SIBs) have become an emerging alternative due to the abundance of raw materials, low cost, and improvements in terms of fast sodium-ion conductor solid electrolytes (SCSEs). Among all the SCSEs, the sodium superionic conductor (NASICON) type electrolyte is one of the most well-known electrolytes, being widely developed in terms of synthesis and materials. However, the processing and manufacturing of these electrolytes have gone almost unnoticed, without considering that well-designed structures of electrodes/electrolytes are the bridge toward turning advanced energy materials into high-performance devices. This work presents the fabrication of 3D complex structures based on NASICON sodium solid electrolytes, obtained for the first time by direct ink writing (DIW). Through a colloidal route, fine NASICON phase powder with high pureness was prepared, enabling the manufacturing of intricate NASICON-printed electrolytes in a one-step fabrication process. By optimizing the ink, a dense electrolyte layer, acting as an ionic conductor and separator, was inserted between two complex porous pattern layers obtaining a device with a total height below 1.15 mm. Further, the densification of the 3D electrolyte was enhanced, reaching high ionic conductivities at room temperature (3.10-4 S·cm-1). Thus, a high-performance sodium ion conductor NASICON solid electrolyte with shorter diffusion pathways and larger interfacial surface areas between electrode/electrolyte was obtained, improving the overall electrochemical performance of the device by a 3D layer-by-layer design.

Obtaining V2(PO4)3 by sodium extraction from single-phase NaxV2(PO4)3 (1 < x < 3) positive electrode materials.

We report on single-phase NaxV2(PO4)3 compositions (1.5 ≤ x ≤ 2.5) of the Na super ionic conductor type, obtained from a straightforward synthesis route. Typically, chemically prepared c-Na2V2(PO4)3, obtained by annealing an equimolar mixture of Na3V2(PO4)3 and NaV2(PO4)3, exhibits a specific sodium-ion distribution (occupancy of the Na(1) site of only 0.66(4)), whereas that of the electrochemically obtained e-Na2V2(PO4)3 (from Na3V2(PO4)3) is close to 1. Unlike conventional Na3V2(PO4)3, when used as positive electrode materials in Na-ion batteries, the NaxV2(PO4)3 compositions lead to unusual single-phase Na+ extraction/insertion mechanisms with continuous voltage changes upon Na+ extraction/insertion. We demonstrate that the average equilibrium operating voltage observed upon Na+ deintercalation from single-phase Na2V2(PO4)3 is increased up to an average value of ~3.70 V versus Na+/Na (thanks to the activation of the V4+/V5+ redox couple) compared to 3.37 V versus Na+/Na in conventional Na3V2(PO4)3, thus leading to an increase in the theoretical energy density from 396.3 Wh kg-1 to 458.1 Wh kg-1. Electrochemical and chemical Na+ deintercalation from c-Na2V2(PO4)3 enables complete Na-ion extraction, increasing energy density.

Microstrip Patch Antenna Design for 5G and Beyond Wireless Communication Systems

This paper gives a theoretical evaluation on how feeder lengths are appropriate for distinct conductor materials using rectangular microstrip patch antenna shape with the help of finite integration techniques (FIT). In this study, the ground surface width is 5.6mm and the ground surface length is 4.65 mm for the rectangular microstrip patch antenna. The length of the patch is 3.44 mm while the patch width is 4.40 mm. The substrate thickness is at 0.20 mm, the patch thickness is 0.035 mm the additional inner feed length is 1.05 mm and the microstrip line feed width is 0.6 mm. Antenna of rectangular microstrip patch type has been designed to work in the 20 – 36 frequency band and working frequency of the proposed antenna is 28 GHz. Compared to the use of a single conductor on the surface of the designed patch antenna, three different conductor materials-copper, gold, and aluminum-were applied to the patch surface of the antenna. The return loss (S11), voltage standing wave ratio (VSWR), bandwidth (BW), directivity and gain of the microstrip antenna parameters are studied using finite integration method Computer Simulation Technology (CST) based on nine different feed lengths in microstrip antenna design. When analyzing the feature of the simulation, the optimal S11 can be observed at the 28 resonant frequencies in the copper conductor. According to the analysis results, for copper conductor the best S11 was obtained at a resonant frequency of 28.03 GHz. The value of S11 is -31.19 dB and the BW value is 968 MHz. For the gold conductor the high return loss is achieved using the at the resonated frequency of 28.01 GHz. S11 value is -32 dB and the BW value is 972 MHz Aluminum conductor has the highest value of S11 with a resonant frequency of 28.01 GHz as shown in -33.29 dB and BW value is 976 MHz. Unsurprisingly, the characterization of the conductor deposition on each structure shows that aluminum conductor yielded the best S11 among all the conductor types. The VSWR is equal to 1.05 for copper conductor at resonant frequency of 28.03 GHz, 1.05 at gold conductor at a resonant frequency of 28.01 and 1.04 for aluminum conductor at a resonant frequency of 28.01 GHz. The maximum directivity values that have been attained in the three-dimensional (3D) representation of the copper conductor, gold and aluminum conductor antennas are nearly 6.99 dBi, respectively. The maximum values of the gain are obtained for the 3D representation of copper, gold and aluminum conductor antennas are 6.61, 6.60 and 6.58 dBi, respectively.

Lifting elementary Abelian covers of curves

Given a Galois cover of curves f over a field of characteristic p, the lifting problem asks whether there exists a Galois cover over a complete mixed characteristic discrete valuation ring whose reduction is f. In this paper, we consider the case where the Galois groups are elementary abelian p-groups. We prove a combinatorial criterion for lifting an elementary abelian p-cover, dependent on the branch loci of lifts of its p-cyclic subcovers. We also study how branch points of a lift coalesce on the special fiber. Finally, for p=2, we analyze lifts for several families of (Z/2)3-covers of various conductor types, both with equidistant branch locus geometry and non-equidistant branch locus geometry.

Polyaniline-Coated Na3V2(PO4)2F3 Cathode Enables Fast Sodium Ion Diffusion and Structural Stability in Rechargeable Batteries.

Na3V2(PO4)2F3 (NVPF), a typical sodium superionic conductor (NASICON) type structure, has attracted much interest as a potential positive electrode in sodium-ion battery. However, the inherently poor electronic conductivity of phosphates compromises the electrochemical properties of this material. Here, we develop a general strategy to improve the electrochemical performance by preparing a new composite material "polyaniline (PANI)@NVPF" using a Pickering emulsion method. The X-ray diffraction and Raman results indicated a successful PANI coating without affecting the NASICON-type structure of NVPF, and they enhanced the interfacial bonding between the two components. Also, thermogravimetric analysis and scanning electron microscopy analyses revealed that the PANI content influenced the thermal stability and morphology of the nanocomposites. As a result, the sodium test cells exhibited multielectron reactions and a better rate performance for PANI@NVPF nanocomposites as compared to NVPF. Specifically, 2%PANI@NVPF maintained 70% of its initial capacity at 5C. Ex-situ electron paramagnetic resonance revealed the existence of mixed valence states of vanadium (V4+/V3+) in both discharge and charge processes. Consequently, the successful PANI coating into the sodium superionic conductor framework improved the sodium diffusion channels with a measurable increase of diffusion coefficients with cycling (ca. 3.25 × 10-11 cm2 s-1). Therefore, PANI@NVPF nanocomposites are promising cathode candidates for high-rate sodium-ion battery applications.

Temperature distribution analysis of gap type conductors and carbon fiber composite core conductors based on finite element

Temperature distribution analysis of gap type conductors and carbon fiber composite core conductors based on finite element

Study on current carrying capacity calculation model for dynamic capacity increase of carbon fiber reinforced composite core conductor

Abstract With the “dual-carbon” as the goal of the new power system construction gradually in-depth, transmission lines must have energy-saving capacity for the direction of development. A new type of large-capacity overhead transmission conductor is the carbon fiber reinforced composite core (CFCC) conductor. The conductor has high capacity, low loss, high-temperature resistance, low high-temperature sag, and other characteristics. It is one of the key technologies and equipment applied to the transformation of old overhead transmission lines to enhance its capacity. At the same time, it can also realize the dynamic transmission capacity regulation of the overhead line. The application of the prospect is very promising. The accurate assessment and calculation model for the conductor’s allowable current carrying capacity is the key core technical problem of the overhead transmission line dynamic capacity increase capability. The paper establishes a maximum allowable current capacity calculation model for carbon fiber-reinforced composite core conductors based on Morgan’s formula. The results of the load flow calculation are compared with the actual load flow test results to verify the calculation model, and the maximum error is 3.59%, which proves the reliability of the calculation model. On this basis, the influence of external environmental factors (ambient temperature, sunlight intensity, wind speed, and direction) on the maximum allowable current capacity of the conductor is discussed. The correlation coefficient of the model is analyzed.

Predicting distribution of aeolian vibration amplitude of undamped overhead transmission lines

The most widely accepted estimation procedure of the severity of aeolian vibration is by calculating the maximum oscillation amplitudes of the conductor using Energy Balance Principle (EBP). However, the EBP is based on wind tunnel results where only one frequency is excited, while observations and experimental results show that multiple resonant modes are excited simultaneously. Furthermore, the required number of cycles of each amplitude level is not provided by current EBP-based methods. In this paper, vibration data from an experimental undamped ACSR Bersfort test line in Quebec, Canada, is recorded and analyzed. For each record of aeolian vibrations, amplitudes are fitted to a Rayleigh distribution based on the narrow-band assumption. The number of cycles and Rayleigh parameter are then related to wind conditions through a modified Strouhal frequency and EBP methodology. A statistical model is proposed to relate vibration profiles and wind input while considering wind turbulence intensity. The proposed method performs well and gives accurate estimates of both vibration amplitudes and number of cycles for ACSR Bersfort conductor. Physical and statistical theory is provided for each step of the method in order to extend the application of the method to other types of conductors or different line configurations.

Molecular Intercalation‐Induced Two‐Phase Evolution Engineering of 1T and 2H‐MS2 (M = Mo, V, W) for Interface‐Polarization‐Enhanced Electromagnetic Absorbers

AbstractPolarization at interfaces is an important loss mechanism for electromagnetic wave (EMW) attenuation, though the motion behavior of carriers in interfaces composed of different types of conductors has yet to be investigated. Tuning the phase structure of transition metal dichalcogenides (TMDs) MS2 (M = Mo, V, W) by organics small molecule intercalation to achieve the modulation of interfacial types is an effective strategy, where 1T‐MS2 exhibits metallic properties and 2H‐MS2 has semiconducting properties. To exclude the contribution of the intrinsic properties of TMDs materials, three TMDs (MoS2, VS2, and WS2), which also possess phase transitions, are investigated. Among them, the 1T‐MS2 composite exhibits excellent EMW absorption performance under the synergistic effect of interfacial polarization and conduction loss. 1T‐MoS2/MOF‐A exhibits the best EMW absorption performance with an RLmin of −61.07 dB at a thickness of 3.0 mm and an EAB of 7.2 GHz at 2.3 mm. The effectiveness of the modulation of the interfacial polarization using 1T‐phase and 2H‐phase MS2 is demonstrated, which is important for the analysis of the carrier motion behavior during the interfacial loss.

Analyzing the role of emissivity in stranded conductors for overhead power lines

Emissivity and absorptivity are important parameters in overhead power line conductors that depend on the conductor surface condition, so their values change as the conductors age. They have an important effect on their thermal behavior, so it is important to know their value when designing dynamic line rating (DLR) strategies. DLR methods are becoming increasingly important, especially in areas with congested power lines, as they allow the full capacity of the lines to be utilized by dynamically determining their maximum allowable currents without exceeding the safe temperature limits of the conductors, thus ensuring that they operate within safe limits. However, measuring emissivity and absorptivity is non-trivial and requires complex tests that cannot be performed in the field. Using simulations based on a realistic thermoelectric model and experimental tests performed on three types of transmission line conductors in a high-current laboratory, this paper shows the importance and effect of emissivity on conductor temperature. It also presents a method for measuring the emissivity value based on adjusting the emissivity and absorptivity values in the thermoelectric model to match the experimental values. The results presented show that aged conductors allow an increase in the maximum current carrying capacity compared to new conductors in the order of 5–14 %, depending on the conductor type considered and the operating conditions.

Interpretation of molecular electron transport in ab initio many-electron framework incorporating zero-point nuclear motion effects.

A computational methodology, founded on chemical concepts, is presented for interpreting the role of nuclear motion in the electron transport through single-molecule junctions (SMJ) using many-electron ab initio quantum chemical calculations. Within this approach the many-electron states of the system, computed at the SOS-ADC(2) level, are followed along the individual normal modes of the encapsulated molecules. The inspection of the changes in the partial charge distribution of the many-electron states allows the quantification of the electron transport and the estimation of transmission probabilities. This analysis improves the understanding of the relationship between internal motions and electron transport. Two SMJ model systems are studied for validation purposes, constructed from a conductor (BDA, benzene-1,4-diamine) and an insulator molecule (DABCO, 1,4-diazabicyclo[2.2.2]octane). The trends of the resulting transmission probabilities are in agreement with the experimental observations, demonstrating the capability of the approach to distinguish between conductor and insulator type systems, thereby offering a straightforward and cost-effective tool for such classifications via quantum chemical calculations.

Lightweight clad bi-metal conductors for cryogenic applications

Lightweight cryogenic conductors are required for applications in electric propulsion, such as cryogenically-fueled electric airplanes and ships. Clad bi-metal conductors allow to consider certain conductor metals that would not be feasible as a single conductor. This includes materials that are chemically reactive and materials that would not have the right mechanical properties to draw wires. The Ashby method is used to compare material combinations systematically. Manufacturing techniques and applications are also discussed. Copper-clad lithium wire stands out as one of the promising new types of clad bi-metal conductors for cryogenic applications.

Compositing pine pollen derived carbon matrix with Na4FeV(PO4)3 nanoparticle for cost-effective sodium-ion batteries cathode

Na super-ion conductor type material Na3V2(PO4)3 has been widely researched as the cathode of sodium-ion batteries (SIBs) in recent years, but the unsatisfying cost of Na3V2(PO4)3 impedes its wide application in SIBs. In this study, iron element is used to replace part of vanadium in Na3V2(PO4)3 to reduce its expense, and pine pollen is applied for the first time as a very effective carbon source to improve the performance of Na4FeV(PO4)3. The fabricated composite material achieves a capacity of 105 mA h g−1 under 0.2 C and fascinating cycling stability over 94 % under 2 C for 500 cycles and 98 % under 10 C for 1000 cycles. The excellent cycle performance is caused by the involvement of pine pollen that acts as a carbon matrix to enhance the electron conductivity and block the agglomeration of active material effectively, thus the well-dispersed nano sized Na4FeV(PO4)3 shortens the diffusion path of sodium ion and gains a remarkable rate capability. Moreover, the distinguished reversibility during the charge and discharge procedures is ascribed also to the robust structure of Na4FeV(PO4)3. This work provides an efficient route to realize the economic cathode material of SIBs with good performance.

Enabling magnetic pulse welding for dissimilar tubular arrester cable joints

Climate change exacerbates the need for resource-efficient and cost-effective production processes across manifold industries, including the field of electrical connections. This specific field is characterized by a conflict of objectives, i.e., weight reductions while maintaining joint strength and electrical conductivity. From a material point of view, the use of aluminum as a conductor material is suitable for this application, as it is lighter than copper, a classical conductor material. Electrical conductors are often used in the form of flexible cables, so-called stranded wires. This type of conductor as well as the fact that the sole use of aluminum in electrical systems is not feasible, e.g., because the predetermined connection terminals of power electronic components are made of copper, creates a substantial demand for dissimilar aluminum-copper cable arrester joints. However, traditional fusion-based welding processes have proved incapable of reliably producing these dissimilar aluminum-copper joints because of thermophysical effects and chemical incompatibilities, the latter eventually leading to the formation of intermetallic phases. These phases adversely affect the quality of the joint in terms of both mechanical and electrical performance. Yet, magnetic pulse welding, a pressure welding process, is ideally suited for producing dissimilar metal joints on the basis of a low energy input during the welding process. Consequently, the formation of intermetallic phases is restrained. However, magnetic pulse welding has not been sufficiently investigated for the reliable contacting of stranded cables to tubular arresters. As a result, this paper focuses on the fabrication of tubular stranded cable arrester joints using magnetic pulse welding. To shed light on possible material combinations, aluminum-to-aluminum and copper-to-copper joints as well as their dissimilar counterparts are welded. Subsequently, the joints are characterized with regard to their microstructure and quasi-static material strength. Electrical characterization comprises the four-wire Kelvin measurement method to evaluate the resistance of the electrical joints. The results demonstrate that magnetic pulse welding is ideally suited to join the aforementioned material combination and joint configuration due to its process characteristics eventually leading to material continuity. As a result, the stranded wires are welded to the tubular arresters rather than crimped. Consequently, a comparative analysis of the joint properties with those of the joining partners shows that the measured electrical resistances and mechanical tensile forces may be considered very good.

Feasibility analysis of dynamic improvement of current carrying capacity of overhead lines

The demand for electricity in China has been increasing year by year. However, the construction of transmission lines is costly and has significant composite short-term peak characteristics. This article aims to study the feasibility of improving the conductor’s current capacity, analyze data characteristics of typical conductor states and micrometeorological data, figure out the real-time conductor’s current capacity based on the calculation model, analyze the margin for improving the CCC, and lift the power supply potential.

ANALISIS SISTEM KELISTRIKAN PADA LABORATORIUM CENTRAL SERVICE KUALA NAMU

Kuala Namu Central Service Laboratory is a laboratory that provides service-based services for electrical and electronic equipment specifically at kuala namu airport equipment. This laboratory uses a lot of laboratory equipment that uses electrical energy. The purpose of this study is to analyse the electrical system on electrical power consumption in the Kuala Namu Central Service Laboratory as well as conduct an analysis between the electrical system of the Kuala Namu Central Service Laboratory with the General Requirements for Electrical Installation and SPLN. Based on the calculation results in the discussion results obtained total power consumption of equipment around 86,637.30 W, from the measurement of operating power of 82,606.66 W. While according to the simulation results using DIg SILENT Power Factory 15.1 .7, the power is 82,604.95 W. The percentage of transformer loading is obtained at 44.08%, this already includes loading according to SPLN standards, while the percentage of generator loading is 89.496% which is declared overloaded. In the simulation results the transformer is 44.08% and the generator is 89.5%. The type of conductor and safety installed as well as the grounding resistance in the building has met the PUIL (General Requirements for Electrical Installation) standard. The grounding resistance of the CPS laboratory building is 2.6 Ω (5 Ω).

A crown-ether-enabled eutectic electrolyte for ultra-high temperature lithium metal batteries

Lithium metal batteries (LMBs) are generally restricted to operating below 60 °C and not suitable for high-temperature applications due to their thermally susceptible carbonate electrolytes. Deep eutectic electrolytes (DEE) with strong supramolecular interactions are a new emerging type of liquid-state ionic conductors, and here we present a novel DEE—which is composed of 18-crown-6 ether (18C6) and lithium difluoro(oxalate)borate (LiDFOB)—to extend the working temperature up to 150 °C. Via combined physiochemical and theoretical characterizations, it is identified that such high thermotolerance is a result of specific solvation structure of Li(18C6)4DFOB with multiple Li–O interactions. Moreover, our newly developed DEE triggers the formation of a B/F-rich solid electrolyte interphase, contributing to superior thermal stability and enhanced compatibility with Li-metal anodes. Consequently, Li|DEE|LiFePO4 cell exhibits great tolerance to extremely high temperatures with a capacity reversibility of 83 % after 250 cycles at 120 °C. Even at 150 °C, the cell can retain 77 % of the initial capacity (105 mAh g−1) after 100 cycles. To our knowledge, the DEE is the first liquid electrolyte for LMBs working at unprecedented high-temperature. This work opens intriguing perspectives to design novel electrolytes for demanded performance of LMBs across a wide temperature range.