Wire Insulation Research Articles

A neural network model for predicting the temperature of insulated overhead lines

In this work, we develop a neural network model based on experimental heating and cooling curves of insulated wires of overhead lines under changes in wind speed and its direction relative to the wire axis. Insulated SIP-3 wire used in overhead lines was investigated. A multilayer perceptron neural network was employed to model the process of heating and cooling of insulated wire under changes in wind speed and its direction. The average absolute error was taken as a criterion for evaluating the prediction accuracy of wire core and insulation temperatures. The main parameters of the developed neural network model include the number of hidden layers and neurons in each hidden layer, the degree of regulation, and the regulatory rigidity of the model. The modelled heating and cooling curves of insulated wire were compared with those obtained experimentally. The average absolute error was equal to 1.74 and –4.08°C for the predicted core and insulation temperatures, respectively. The difference between the heating curves at low wind speeds was found to range within 9°C. It was shown that an increase in wind speed leads to a decrease in the difference between the curves. Our analysis showed that neural network models used for predicting variations in the temperature of insulated overhead lines should be trained using a larger number of input parameters. This is the main prerequisite for high prediction accuracy of such models, when the difference between the simulated and experimental data does not exceed 5%.

Dielectrophoretic capture of Escherichia coli and boar sperms using ULSI-fabricated three-dimensional protruding TiN nano-electrode arrays.

In recent years, dielectrophoresis has become widely recognized as a highly suitable method for creating good tools for particle separation, with significant successes achieved in a variety of areas. Expanding upon this, we adopted a semiconductor CMOS process, instead of a MEMS process, which allowed for the following: 1) wire insulation to mitigate Joule heat and prevent thermal fluctuation interference with the dielectrophoretic force; 2) isolation of harmful materials from biological samples, making the chip biocompatible; and, 3) the ability to employ nano-electrodes capable of generating a stronger electric field than conventional electrodes, thus allowing chip capture at lower voltages. Additionally, our chip is scalable, enabling multiplied throughput based on sample processing requirements. These features make our chip more widely applicable and suitable for capturing bacteria and sperm. In this study, we focused on optimizing the parameters of dielectrophoresis and employed 3-D protruding TiN nano-electrode arrays to facilitate the capture of Escherichia coli and boar sperms. The experimental data demonstrates that the capture efficiency of this chip for E. coli was approximately 79.25% ± 2.66%, and the highest capture efficiency for sperms was approximately 39.2% ± 3.9%.

High-frequency transients in buried insulated wires: Transmission line simulations and experimental validation

This paper presents experimental results on the transient response of a buried insulated wire subjected to fast transient signals. It reports measurements of voltage and current at the sending end, as well as the voltage at the receiving end of the insulated wire. The obtained experimental results are utilized to assess the accuracy of recent formulations proposed for computing the ground-return impedance and admittance of underground cables, which are important for simulation of transients using models based on the transmission line theory. The good agreement between measurements and simulations bolsters confidence in incorporating these newly proposed expressions for computing the cable's ground-return parameters into EMT-type simulators.

Fillet Radius Impact of Rectangular Insulated Wires on PDIV for Turn-to-Turn Insulation of Inverter-Fed Motors

Fillet Radius Impact of Rectangular Insulated Wires on PDIV for Turn-to-Turn Insulation of Inverter-Fed Motors

Characterization of cement–slime mixture using time domain reflectometry

This study explores the electromagnetic characteristics of five cement–slime mixtures using two types of time domain reflectometry sensors. For 28 days of curing, compressive strength tests are conducted and electromagnetic signals are measured. The electromagnetic wave velocity and corresponding apparent permittivity are calculated, and the relationships between these properties and the compressive strengths of the mixtures are established. Results show that in the initial curing period, capturing the apparent permittivity using a conventional probe proves difficult due to the high electrical conductivity of the mixtures. In contrast, an insulated electrical wire can detect reflected signals across all slime ratios, but it exhibits less sensitivity to changes in the electromagnetic signal. The apparent permittivity decreases exponentially over the curing time, influenced by the hydration process. Strong correlations are found between the apparent permittivities derived from both sensors and between decreasing apparent permittivity and increasing compressive strength.

Modelling of opposed flame spread over thin electric wires: estimation of flame spread rates and limiting oxygen concentrations

A model of opposed flame spread along thin electric wires is developed to estimate the variation of flame spread rate ( V f ) with oxygen concentrations and oxidiser flow velocity. The length of pyrolysis zone ( L py ) and V f are treated as eigenvalues of the problem, and one-dimensional energy balance equations for the wire core and insulation are formulated to derive their solutions. To obtain a set of steady solutions for L py and V f , the macroscopic energy balance equation for the entire system is calculated from the one-dimensional energy balance equations with appropriate boundary conditions. Since the equations are nonlinear function of L py and V f , multiple solutions appear. The physical meaning of each solution is evaluated based on the deviation of energy from the equilibrium. Comparison of the temperature distribution along the wire with experimental data confirms that the model reproduces well the actual flame spread process. The variation of V f with oxygen concentration shows a C-shaped curve. The upper branch is the stable solution, and the lower branch is the unstable solution and the merging point of two branches correspond to the limit condition for flame spread. Therefore, the model can be used to estimate the limiting oxygen concentration based on the existence of a solution for V f . Furthermore, the variation of V f with oxidiser flow velocity shows O-shaped curve, and it is confirmed that radiative extinction under low flow velocity and blow-off under high flow velocity can also be estimated with the model. Mapping of variations of radiative extinction and blow-off extinction with oxygen concentration reveals the U-shaped flammability diagram. The predicted flame spread limits are in good agreement with the limiting oxygen concentrations measured in both microgravity and normal gravity, demonstrating the validity of using this model to predict flammability characteristics of electric wires under various oxidiser flow velocity.

Design of filtering cable with defected conductor layer

Electrical cables, often referred to as ‘blood vessels’ and ‘nerves’ of the industry, play a vital role in the connection of electrical devices. However, traditional cables that lack distributed filtering functions are usually the primary coupling path for electromagnetic compatibility (EMC) problems. An innovative design for a filtering cable, which incorporates insulated electrical wires coated with a specific defected conductor layer (DCL), enables it to achieve distributed filtering advantages along its axis. Microwave network analysis is employed to build the two-port network model of filtering cable, which efficiently analyzes the cascading characteristics of periodic or aperiodic filtering cables. To validate, the flexible printed circuit board (FPCB) with sawtooth dumbbell-shaped DCL and mounted by capacitors is wrapped around the stripped section of the coaxial cable to manufacture a multi-stopband filtering cable. Simulated and measured results demonstrate that the proposed filtering cable can be effectively suppressed in the stopband, which can be adjusted by changing the values of capacitors.

Modification of thermal and electrical characteristics of hybrid polymer nanocomposites through gamma irradiation for advanced applications

In this article, we present a straightforward in-situ approach for producing Ag NPs incorporated in graphene oxide (GO) blended with glutaraldehyde (GA) cross-linked polyvinyl alcohol (PVA) matrix. Samples are γ-irradiated by doses of 2, 5, and 10 kGy and in comparison with the pristine films, the thermal conductivity (‘k’) and effusivity are measured. ‘k’ decreases with irradiation doses up to 5 kGy and further increase in the dosage results increase in ‘k’. We performed FDTD modeling to verify the effect of polarization and periodicity on the absorptivity and emissivity spectra that are correlated to the ‘k’ and effusivity, empirically. Hence, we can confess that the structural properties of the prepared hybrid nanocomposite are manipulated by γ-irradiation. This attests that the PVA/GO-Ag/GA nanocomposite is radiation-sensitive and could be employed for thermal management systems. Moreover, their strong electrical insulation, as the measured dc conductivity of the γ-irradiated samples is found to be in the range of 2.66 × 10−8–4.319 × 10−7 Sm−1, which is below the percolation threshold of 1.0 × 10−6 Sm−1, demonstrates that they are excellent candidates for the use of thermal management materials. The low ‘k’ values allow us to use this promising material as thermal insulating substrates in microsensors and microsystems. They are also great choices for usage as wire and cable insulation in nuclear reactors due to their superior electrical insulation.Graphical

Assessment of Edgewise Insulated Wire Bend Radius Impact on Dielectric Properties of Turn-to-Turn Insulation Through Thermal Aging

Assessment of Edgewise Insulated Wire Bend Radius Impact on Dielectric Properties of Turn-to-Turn Insulation Through Thermal Aging

РАЗРАБОТКА ИНВЕСТИЦИОННОГО ПРОЕКТА ПО ОТКРЫТИЮ ОТДЕЛА МОНИТОРИНГА ЭЛЕКТРОЛИНИЙ

This article analyzes the financial and economic activities of a commercial enterprise, taking into account all the necessary indicators for the development and implementation of measures that increase the economic efficiency of the organization. The development of an investment project to open a monitoring department in PJSC ROSSETI Kuban is being considered. The development of investment policy stimulates the development of business and science, as well as contributes to solving social problems in society. To stabilize and improve production efficiency, PJSC ROSSETI Kuban has developed an investment project to create a department for monitoring electrical lines and upgrade them to modern self-supporting insulated wires (SIP). Calculations were made on the costs and expenses for the implementation of the proposed project. The analysis of the project showed its feasibility and effectiveness. Thus, the implementation of this investment project will allow PJSC ROSSETI Kuban to achieve its goals, including increasing profitability and profit, improving financial autonomy and sustainability. The implementation of M&A will ensure the reliability and safety of power supply, minimize power losses and reduce maintenance and repair costs. It will also create additional jobs and improve the environmental situation by reducing the number of emergency shutdowns and reducing network losses. The purpose of this article is to ensure the economic security of an organization in a competitive market. The analysis carried out and the measures developed will help PJSC ROSSETI Kuban strengthen its position in the market, improve the quality of services provided and contribute to the sustainable development of the company in the long term.

Life Characterization of PEEK and Nanofilled Enamel Insulated Wires Under Thermal Ageing

Life Characterization of PEEK and Nanofilled Enamel Insulated Wires Under Thermal Ageing

ВНЕДРЕНИЕ ИНВЕСТИЦИОННОГО ПРОЕКТА КАК ИНСТРУМЕНТ ПОВЫШЕНИЯ ЭФФЕКТИВНОСТИ

Investment policy is a key tool used by the state to create stable and develop business entities. It is a set of actions and decisions aimed at supporting investment activities. The essence of investment policy is to create conditions for long-term economic growth. A well-designed investment policy can activate investment activity, stimulate the development of business and science, as well as contribute to solving social problems in society. To stabilize and improve production efficiency in PJSC Rosseti Kuban, an investment project was developed to create a department for monitoring electrical lines and upgrade them to modern self-supporting insulated wires (SIP). The analysis of the project showed its feasibility and effectiveness. Thus, the implementation of this investment project will allow PJSC Rosseti Kuban to achieve its goals, including increasing profitability and profit, improving financial autonomy and sustainability. Ultimately, this will ensure the long-term economic security of the company.

Three-Electrode Coin Cell with Gold Micro-Reference Electrode

As the demand for Li-ion batteries continues to grow, accelerating their development is crucial. An essential aspect of enhancing battery performance involves obtaining a deeper understanding of fundamental electrochemical processes. This understanding can be achieved by applying advanced measurement techniques such as electrochemical impedance spectroscopy (EIS), a promising method for investigating batteries, providing insights into reactions, material properties, and interphases.1 However, when EIS is conducted on a full cell, the resulting spectra combine information from both electrodes, limiting the characterization of each electrode.2 To deconvolute the influence of the electrodes, a three-electrode setup can be used. This setup introduces a reference electrode (RE) which allows deconvolution of the full cell impedance into the impedance of the separate electrodes.The choice and placement of the RE significantly impact impedance spectra.3 Ideally, the RE should maintain a stable potential, allow ion flow, and not obstruct any part of the other electrodes.4 Micro-REs are often favored for EIS due to these considerations. Additionally, the RE placement can distort impedance spectra if positioned in a geometrically or electrically asymmetric region of the cell.3 Several cell designs have been proposed for three-electrode configurations.4 An innovative approach incorporates a gold micro-RE into a Swagelok T-cell setup.5 This work involves a 50 µm thick insulated gold wire sandwiched between two separators which could be lithiated to form a gold-Li alloy at its tip. This lithiated tip shows a stable potential for extended periods, resulting in reliable impedance spectra of the electrodes. While the proposed setup has been instrumental in facilitating valuable research, the cell format has room for improvement. Even though effective, Swagelok T-cells come with high costs and require intricate assembly. Furthermore, disassembly, cleaning, and drying of cell components for re-use substantially prolong the preparation time. Other studies have explored the coin cell format for the three-electrode setup4, offering several advantages, including simplified and rapid assembly procedures. Moreover, the disposable nature of this cell format significantly reduces unit costs and shortens preparation times. Consequently, some researchers have sought to leverage these benefits by incorporating the RE through a coaxial configuration within a hole in the electrodes.4 However, these adaptations often necessitate substantial modifications to cell components and electrodes and are not well-suited for reliable impedance measurements. In some other approaches that involve placing the RE between separators and electrodes4, achieving consistent cell assembly appears to be a persistent challenge, and cell sealing issues may arise in these setups as well.In this work, we have devised a reliable, cost-efficient approach for three-electrode coin cell construction that employs common coin cell parts. Our approach eliminates the need for specialized tools, relying instead on conventional laboratory-scale equipment and accessible commercial materials. In this configuration, as depicted in the inset of Fig.1, the assembly process is carefully adapted so that the micro-RE wire remains straight and lies as flat as possible throughout the cell, positioned between the electrodes and separators. The sealing in our setup is ensured with a special resin compatible with the micro-RE and the components inside the cell, effectively preventing the penetration of moisture and/or air into the cell. We have validated the effectiveness of this sealing method by electrochemical tests that are sensitive to the water and oxygen content within the cell (see Fig. 1). Here, we present comprehensive details about the assembly modifications and custom-designed cell holder. This study also includes examples of measurement results, especially impedance spectra. The proposed setup holds significant promise for various applications in research laboratories and industrial settings, enabling fast, reliable, and cost-efficient setup for impedance characterization tests.

Research and Development of Discharge Free Insulation of Wires for Space Application

Research and Development of Discharge Free Insulation of Wires for Space Application

Investigation and characterization of dielectric, thermal, and chemical properties of recycledhigh‐density polyethyleneblended with virginpolyethylene

AbstractDielectric performance of post‐consumer recycled HDPE blended with virgin HDPE was investigated to evaluate the possibility of using these materials for the insulation of electrical wires and cables. The presence of organic and inorganic impurities was investigated using thermal and chemical methods (TGA, DSC, and EDX). The characterization of impurities revealed different amount of inorganic impurities in recycled material that was depending on the execution of melt filtration by the recycler to prepare the recycled material. Higher values of both dielectric losses and dielectric constant were observed for post‐consumer recycled PE, with the dielectric loss of recycled material almost 17 times higher than the one of virgin PE at power frequency (60 Hz). The short‐term breakdown strength of post‐consumer recycled HDPE was observed to be slightly lower than that of virgin PE. The experimental result showed that blending the recycled stream with virgin materials was effective in order to enhance dielectric properties of recycled material. In this regards, dielectric losses decreased by almost 50% when 50% of virgin HDPE was added to the recycled material. In addition, breakdown strength was improved when virgin HDPE was added.

Injury hazard assessment in schools: Findings from a pilot study in Karachi, Pakistan

IntroductionInjuries are a major public health concern and one of the leading causes of death and disability worldwide. Childhood injuries contribute to a major proportion of this burden. ObjectiveTo identify injury hazards within school premises and playgrounds in Karachi, Pakistan. MethodsThis observational cross-sectional study took place in 107 public and private schools of Karachi, Pakistan using a self-structured standard injury risk assessment tool. This tool was developed after an extensive literature review, expert consultation, and field visits to a few local schools. Data related to school demographics, administrative data and injury hazards within the school boundaries were collected in schools offering education from nursery to secondary grades (through 10th grade, matriculation). Descriptive analysis were calculated. ResultsOut of 107 schools, only 12 were recording school-related injuries. A quarter (25%) of schools had some type of disaster drill exercises and built-in fire exits. Fire alarms were placed in 10 schools (9%), all of which were private. In 16 schools (15%), students had access to rooftop doors. There were multiple injury hazards in the school playgrounds. More than half of the schools had hazardous playground surfaces, such as slippery, concrete and uneven ground. Over 80% of schools were not supervising the children during playtime and did not have a separate play area for children under 6 years old. In 38 schools (22%), there were multiple injury hazards in the play rides, such as broken equipment, rusted parts, and sharp edges. Moreover, nine schools (7%) had loose nuts, bolts, edges, belts, steps, or rails in their play rides. Inside, almost a quarter (24%, n = 76) of schools did not have proper insulation of electric wires. Protruded metal nails, which could be high risk for prick and cut injuries, were observed in 20% of the observed furniture. ConclusionIn conclusion, there are multiple injury hazards in the private and public schools of Karachi, Pakistan.

Method for detecting the source of radio interference affecting train radio communication in the band of 2.13 and 2.15 MHz

There are many factors that infl uence the process of organising train movements, quality radio communication being one of the most important. The intelligibility of the dispatcher’s commands to the driver is important in deciding what action to take, and in informing the dispatcher of the train situation on a particular section of the track. Sources of radio interference that have an interfering effect on the quality of the train radio signal are natural and artifi cial interference. The sources are mainly low-frequency interference. One of the constant sources of high-frequency emissions that affect stable operation of train radio communications refers to discharges generated in the high-voltage insulation of power lines, including discharges generated in the insulation of overhead wires. Spark discharges, the source of radio interference, occur both on the surface of the insulator (usually called surface partial discharges (SPD)) and inside the insulation (such discharges are called partial discharges (PD)). In the operation of high voltage insulation, those insulators that contain PD and PPD are called defective insulators. PD and PD diagnostics are carried out twice a year by means of a laboratory car. Discharge registration is performed in the visible and ultraviolet range. There are acoustic methods for registering PD and SPD. It is proposed to register discharges in the electromagnetic frequency range. For prompt detection radio interference, it is recommended to place antennas on the laboratory car, and combine measurements with current diagnostics of high-voltage insulation, that will allow increasing reliability of the results received in the course of diagnostics. To increase the accuracy of radio interference source detection, two antennas are considered to be placed on the laboratory car.

Solvay launches new compound e-motor magnet wire insulation, renews collaboration with GKN Aerospace and expands industrial FFKM portfolio

On May 23, 2023, Solvay announced the launch of KetaSpire® KT-857, a new polyetheretherketone (PEEK) extrusion compound designed especially for copper magnet wire insulation in electric motors. The development of the custom-engineered insulation material was driven by the move of OEMs towards higher density batteries and electric powertrains operating at 800V or above to address the range anxiety of consumers.

Insulated, Passivated & Adhesively-Promoted Bond Wire Using All-in-One Al2O3 Coating

Insulated, Passivated & Adhesively-Promoted Bond Wire Using All-in-One Al2O3 Coating

Preparation of Polyurethane-Modified Silicone Rubber Insulating Coating and Its Application in 10 kV Overhead Bare Wire Wrapping

Room-temperature vulcanized rubber is an excellent polymer material with excellent electrical insulation and mechanical properties, which can be used for field insulation of high-voltage bare wire. In this paper, a room-temperature cured coating material was prepared from α,ω-dihydroxy polydimethylsiloxane (PDMS), polyurethane-modified silicone material (PU-Si), and Methyltris(methylethylketoxime) silane (MOS). The study showed that the coating made by adding PDMS (70 g), PU-Si (30 g), CaCO3 (90 g), MOS (7 g), KH792 (5 g), and Mg(OH)2 (30 g) had a surface drying time of 19.1 min, tensile strength of 3.2 Mpa, volume resistivity greater than 4 × 1014 Ω·cm, breakdown voltage greater than 20 kV/mm, and flame retardant performance of the FV-1 level. The comprehensive performance of the insulation material meets the national standard of “Aerial insulated cables for rated voltage of 10 kV” (GB/T14049-2008), while the insulation material has been successfully applied to the overhead line renovation project of the State Grid Hubei Electric Power Company (Wuhan, China).