Electric Power Lines Research Articles

Effects of mercury and magnetic fields on the activity of proteinases and glycosidases in the intestine of common carp Cyprinus carpio.

Aquatic ecosystems are increasingly affected by anthropogenic pollution, including heavy metals like mercury, which accumulate in organisms and cause harmful effects. At the same time, human activities such as industrial operations and the use of electric power lines also alter the magnetic background in natural water bodies. However, the interaction between mercury exposure and magnetic fields remains poorly understood. This study aimed to investigate the combined effects of mercury and magnetic fields on the digestive enzyme activity of common carp (Cyprinus carpio), focusing on the relevance of magnetic fields due to their increasing presence in industrialized environments. Two groups of fish were fed diets with low (0.02mg/kg) or high (0.27mg/kg) mercury content for 6months and exposed to extremely low-frequency magnetic fields or hypomagnetic conditions. Results showed significant differences in mercury accumulation between groups, with higher levels in carps fed with high-mercury content diets. These fish also exhibited increased body length and weight compared to those on a low-mercury diet. The amylolytic activity (total activity of enzymes hydrolyzing starch: α-amylase, glucoamylase, and maltase) and proteolytic activity (total activity of serine proteinases) in the fish intestine were assessed. Magnetic exposure had contrasting effects on enzyme activity, depending on mercury levels in the diet. Fish fed the low-mercury diet exhibited decreased amylolytic activity following magnetic field exposure, while fish on the high-mercury diet showed increased activity. Proteolytic activity followed a similar pattern, with opposite effects observed between the two dietary groups. These findings suggest that mercury accumulation alters the biological response to magnetic fields, possibly through compensatory biochemical mechanisms. Understanding the interactions between toxic substances and magnetic fields is critical for improving environmental risk assessments.

Testing and analysis of a D-STATCOM prototype connected to the electrical network

In this article Flexible AC Transmission Systems (FACTS) devices are addressed, especially the design and implementation of a D-STATCOM prototype, making a comparison between the theoretical behavior and the aforementioned prototype. A fuzzy logic-based strategy was used for voltage control, employing the Matlab Fuzzy Logic Designer tool. The neural network was trainned with the network voltage, the voltage of the inverter stage, the current, the active and reactive power, and the power factor as inputs. Initially, the load power factor was 0.62 and the prototype operation allowed the voltage to be increased above the grid voltage, which is reflected in the forward current, modifying the power factor to a value of 0.91 while maintaining the same voltage. Finally, the results demonstrate the relationship between the increase of the inverter stage of the prototype above the electrical power line, obtaining a variable capacitor thus adjusting the power factor.

A High Gain, Low Power Operational Transconductance Amplifier Capable of Recording and Processing ECG Signals

Based on high output resistor current mirrors and differential pair inputs, a new operational transconductance amplifier (OTA) is designed in this paper that can collect, filter, denoise and amplify electrocardiogram (ECG) signals. The OTA is designed on a 0.18μm CMOS process with a supply voltage of 1.8V. In this experiment, the ECG signal generated by the human model is first simulated, which has a noise of 50 Hz from electromagnetic interference, especially the electrical power lines. The differential input pair is then connected to the model, and it is proved that it can denoise the common-mode noise. Finally, the designed OTA is connected to the manikin, and the experimental results are compared with the traditional OTA. The design achieves a differential-mode gain of 43.56dB and a common-mode gain of -31.36dB while maintaining a differential input voltage swing of 1Vpp. Experimental results show that the OTA can denoise and amplify the ECG signal without distortion.

Analytical solution of conductor tensile force in asymmetrical spans used in overhead power lines and substations with influence of tension insulators

Introduction. Designing electrical substations involves analyzing the horizontal tensile force in flexible tension conductors under varying temperatures. These temperature changes affect the conductor’s length and forces. Problem. Existing methods for calculating horizontal tensile force in conductors often focus on symmetric spans or require complex finite element modeling (FEM), which is impractical for routine substation design. Asymmetric spans with tension insulators present a more complex challenge that current solutions do not adequately address. Purpose. Universal analytical solution and algorithm for calculating the horizontal tensile forces in conductors in asymmetric spans with tension insulators used in power substations or short overhead power line spans. The solution is designed to be easily implementable in software without requiring complex tools or extensive FEM. Methodology. The methodology involves deriving an analytical solution based on the catenary curve formed by the conductor between attachment points at different heights. The analysis includes calculating the conductor’s length for a given tensile force and using a state change equation to determine forces under new temperature conditions. Validation is performed using FEM calculations. Results. The proposed solution was validated against FEM models with varying height differences (5 m and 15 m) and conductor temperatures (–30 °C, –5 °C, +80 °C). The results showed a minimal error (less than 0.15 %) between the analytical solution and FEM results, demonstrating high accuracy. Originality. This paper presents a novel analytical solution to the problem of calculating tensile forces in asymmetric spans with tension insulators. Unlike existing methods, our solution is straightforward and easily implementable in any programming language. Practical value. The solution is practical for routine design tasks in electrical substations or short overhead power lines. Especially in power substations, accurate tensile forces are needed not only for mechanical design and sag calculations but also for calculating the dynamic effects of short-circuit currents. References 23, tables 4, figures 3.

Analysis of Influence of Wiring Error on Electric Energy Metering Device and Preventive Measures

Electric energy metering device is the key to ensure the economic interests of power supply enterprises and users and the safety of electricity. Wiring errors are the main causes of electric energy metering distortion and power line failure. Five types of wiring errors of electric energy metering devices and their possible effects are described and sorted out, and the corresponding detection methods for software and hardware wiring errors are introduced. Based on the actual application of the electric energy metering device, the corresponding preventive measures are put forward, in order to provide some reference for solving the problem of wiring errors in the metering system of the electric energy metering device and ensuring the safety of electricity use.

Uncertainty-aware deep learning for monitoring and fault diagnosis from synthetic data

Deep neural networks (DNNs) are often coupled with physics-based and data-driven models to perform fault detection and health monitoring. The system models serve as digital surrogates that generate large quantities of data for training DNNs which would otherwise be difficult to obtain from the real-life system. In such a scenario, the uncertainty in the system model and in the DNN parameters will influence the predictions of the DNN. Here, we quantify the impact of this uncertainty on the performance of DNNs. The uncertainty from the system model is captured with two methods, namely assumed density filtering and heteroskedastic modelling. In addition to quantification, these methods allow training DNNs in an uncertainty-aware manner. The uncertainty in the DNN parameters is captured with Monte Carlo dropout. The proposed approach is demonstrated for fault diagnosis of electric power lines. Data generated from a physics-based model calibrated with real-life measurements is used to train three neural network architectures for fault diagnosis. The results reveal that uncertainty-aware models can provide 1% to 19% improvement in classification accuracy than their deterministic counterparts. The uncertainty-aware models also exhibit better robustness to uncertainty and, thus, offer more reliable models for deployment. Remarkably, the article provides a system-agnostic framework for uncertainty-aware training of DNN models for fault diagnosis and monitoring that explicitly accounts for the synthetic nature of training data.

Identifying Areas of High-Risk Vegetation Encroachment on Electrical Powerlines Using Mobile and Airborne Laser Scanned Point Clouds

Identifying Areas of High-Risk Vegetation Encroachment on Electrical Powerlines Using Mobile and Airborne Laser Scanned Point Clouds

Are friends electric? Valuing the social costs of power lines using house prices

Overhead electrical power lines and pylons have long raised concerns regarding the effects of electromagnetic fields on health, noise pollution and the visual impact on rural landscapes. These issues are once again salient because of the need for new lines to connect sources of renewable energy to the grid. In this study we provide new evidence on the cost implied by these externalities, as revealed in house prices. We use a spatial difference-in-difference approach that compares price changes in neighborhoods that are close to overhead power-lines, before and after they are constructed, with price changes in comparable neighborhoods further away. Our findings suggest that the construction of new overhead pylons reduces prices by 3.9% for properties up to 1500 m away, suggesting the impacts extend further than previously estimated.

Characterizing MIMO Channels in Low-Voltage Electric Power Line Communication through Impedance and Scattering Parameters Analysis

Characterizing MIMO Channels in Low-Voltage Electric Power Line Communication through Impedance and Scattering Parameters Analysis

ERRATUM: Characterizing MIMO Channels in Low-Voltage Electric Power Line Communication through Impedance and Scattering Parameters Analysis

ERRATUM: Characterizing MIMO Channels in Low-Voltage Electric Power Line Communication through Impedance and Scattering Parameters Analysis

Flux potentials of local talc in low voltage electro-porcelain insulator production

Increasing demand for accessories like porcelain electric insulators have continued in developing countries causing overdependence on imported products. Meanwhile, raw materials for their local production are available in commercial quantities with high firing temperature being the major challenge. Hence, the need for fluxing agents that can reduce the working temperature led to the investigation of Talc as a partial replacement of conventional Feldspar. An optimum replacement of 10% Feldspar with Talc was adopted, and this recipe showed microstructurally enriched glassy phase, primary and secondary Mullite with other crystalline phases like Cristobalite, Microcline and Albite at 1200oC with micropores evident in both the Talc and Feldspar formulations. The produced insulator fired at 1200oC offered an optimum thermal conductivity of 0.2768W/mK with reductions in water absorption, apparent porosity and linear shrinkage by 78.29%, 76.02% and 19.75% respectively with a 9.48% rise in bulk density. The electrical performance comprised Inception, Withstand and Breakdown Voltages of 10.2 kV, 14 kV and 20 kV respectively at leakage currents of 0.2 mA, 1.2 mA and 2 mA accordingly. With a withstand voltage above 11 kV and breakdown voltage below 22 kV, this pin-type porcelain insulator will find wide application in both electric substations and end user load points like commercial and residential electric power lines. The novelty lies on the fluxing and filler potentials of Talc as a locally-sourced mineral in porcelain insulator production which increases the market value of Nigerian Talc while reducing importation, costs of energy and raw materials in porcelain production.

Good examples of electrical network security for Lesser Kestrel (Falco naumanni) in SPA Sakar (BG002021)

The overhead electrical power lines, which are part of the electricity distribution network, could be considerable threat to different bird species. The main incidents are related to electrocution and bird`s collision with power lines. The biggest danger comes from electrocution – in these cases birds die as a result of contact with the power line. The electrical current generates electric arc through the bird and the power line and leading to the birds’ instant death. The Green Balkans, as а breeder in SPA Sakar BG 002021 Bulgaria, and under the projects “Lesser Kestrel Recovery” LIFE11 NAT/BG/360 and “LIFE for Lesser Kestrel” LIFE19 NAT/BG/001017 succeeded to recover Lesser Kestrel (Falco naumanni, Fleischer 1818) and among the aims of the project was to take measures to mitigate the threat of electrocution. Among the operational over ground power grid lines in Bulgaria, according to the electrical voltage, the most dangerous and life threatening to birds is the mid voltage power supply grid (20 kV) that is also the main cause for death from electrocution. The Green Balkans` team conducted field research of the dangerous types of pylons, on-site isolation of electricity pylons has been identified within a range of 4.5 km of the Lesser Kestrel colony. According to the way of safeguarding the elements of the electrical grid several different devices were used: “Rigid bird protective cover”, perch guards and bird discouragers. Safeguarding by installation of perches has also been done. The isolation of dangerous pylons in the electrical network ensured safe conditions not only for the Lesser Kestrels, but also for other birds that use the power line elements as landing sites, rest spots, or even for nesting. Keywords: Electrical network, Falco naumanni, Lesser Kestrel, SPA Sakar

Evaluating the resilience of electrical power line outages caused by wildfires

Evaluating the resilience of electrical power line outages caused by wildfires

A Comprehensive Review of Fault Diagnosis and Prognosis Techniques in High Voltage and Medium Voltage Electrical Power Lines

This paper presents an extensive review of the most effective and modern monitoring methods for electrical power lines, with particular attention to high-voltage (HV) and medium-voltage (MV) systems. From a general point of view, the main objective of these techniques is to prevent catastrophic failures by detecting the partial damage or deterioration of components and allowing maintenance operations to be organized. In fact, the protection devices commonly used in transmission and distribution networks guarantee the location of faults, such as short-circuits, putting the non-functioning branch of the network out of service. Nowadays, alongside these devices, it is possible to introduce new intelligent algorithms capable of avoiding the total loss of functionality, thus improving the reliability of the entire network. This is one of the main challenges in modern smart grids, which are characterized by the massive integration of renewable energy sources and a high level of complexity. Therefore, in the first part of this paper, a general overview of the most common protection devices is proposed, followed by an analysis of the most modern prevention algorithms. In the first case, the coordination of the relays plays a fundamental role in obtaining the fault location with a high level of selectivity, while in the field of preventive analysis, it is necessary to address the implementation of artificial intelligence methods. The techniques presented in this paper provide a comprehensive description of the different monitoring approaches currently used in distribution and transmission lines, highlighting the coordination of protection relays, the computational algorithms capable of preventing failures, and the influence of the distributed generation in their management. Therefore, this paper offers an overview of the main diagnostic techniques and protection devices, highlights the critical issues that can be overcome through the introduction of artificial intelligence, and describes the main prognostic methods, focusing on their invasive level and the possibility of operating directly online. This work also highlights the main guidelines for the classification and choice between the different approaches.

Improving the efficiency of medium voltage (MV) distribution lines using risk matrix for optimized maintenance

Medium Voltage overhead lines within North-West power utility companies in South Africa are confronted by higher volumes of deficiencies leading to frequent power failures. An essential quality of service factor considered in power distribution is the electricity supply to customers free of interruptions. Due to the higher number of electrical power line faults associated with the power system life span, achieving the desired level of reliability becomes an enormous task. The paper shares the findings of a study on performance improvement of MV distribution overhead lines using a risk matrix for deficiency analysis and clearing of such defects. A pilot study was conducted, and the risk matrix strategy developed in the study improved the reliability and key performance indicators by trimming down the overhead power line deficiencies. Defect clearing lowered outage frequency, durations, and power losses. The System Average Interruption Duration Index (SAIDI) was enhanced by lowering the outage duration by 108.64 h annually. The System Average Interruption Frequency Index (SAIFI) improved by reducing the outage frequency by 45.45 sustained occurrences annually and Reticulation Supply Loss Index (RSLI) by 8.31 MVA monthly.

Fundamentals of Monitoring Condensation and Frost/Ice Formation in Cold Environments Using Thin-Film Surface-Acoustic-Wave Technology.

Moisture condensation, fogging, and frost or ice formation on structural surfaces cause severe hazards in many industrial components such as aircraft wings, electric power lines, and wind-turbine blades. Surface-acoustic-wave (SAW) technology, which is based on generating and monitoring acoustic waves propagating along structural surfaces, is one of the most promising techniques for monitoring, predicting, and also eliminating these hazards occurring on these surfaces in a cold environment. Monitoring condensation and frost/ice formation using SAW devices is challenging in practical scenarios including sleet, snow, cold rain, strong wind, and low pressure, and such a detection in various ambient conditions can be complex and requires consideration of various key influencing factors. Herein, the influences of various individual factors such as temperature, humidity, and water vapor pressure, as well as combined or multienvironmental dynamic factors, are investigated, all of which lead to either adsorption of water molecules, condensation, and/or frost/ice in a cold environment on the SAW devices. The influences of these parameters on the frequency shifts of the resonant SAW devices are systematically analyzed. Complemented with experimental studies and data from the literature, relationships among the frequency shifts and changes of temperature and other key factors influencing the dynamic phase transitions of water vapor on SAW devices are investigated to provide important guidance for icing detection and monitoring.

Laser percussion drilling of transparent hard and brittle materials with ring-shaped electrodes

This paper presents an innovative approach to detect plasma induced by laser drilling in a laser processing system using an external sensing electric field. The system uses a sensing electrode to detect the plasma signal, which is then sent to the controller in real-time via an embedded signal sampling rate system. The system is capable of accurately sensing the pulse repetition rate from 0 to 500 kHz during laser processing, with a signal sampling rate of up to 1 MHz. The controller analyzes the plasma signal and adjusts the laser focus position by controlling the servo motor to achieve real-time detection of laser drilling. The paper compares several configurations of electric field assistance, including parallel type interdigitated electrodes, mask type interdigitated electrodes, ring shape electrodes, and parallel type interdigitated electrodes without a steel plate. The electric field strength and power line distribution of the electric field were simulated using the COMSOL Multiphysics finite element software, and the system was tested on sapphire and quartz glass. The experimental results showed that in the presence of the electric field, the opening diameter decreased by 8 % and 12.13 %, respectively, for sapphire and quartz glass, compared to the case without the electric field. Moreover, the exit diameter increased by more than 100 % and 49.79 %, the ring shape taper angle decreased by 23.31 % and 33.74 %, the machining time decreased by 66.22 % and more than 40 %, and the opening heat affected zone decreased by 24.45 % and more than 50 %, for sapphire and quartz glass, respectively.

PLPose: An efficient framework for detecting power lines via key points-based pose estimation

The inspection and maintenance of electrical power lines (PL) via unmanned aerial vehicles (UAV) require fast and accurate PL detection to ensure smooth and secure electrical operations. However, the detection of PLs from aerial images is a highly challenging task due to the thin nature of PLs and the inherent noisy image backgrounds. Traditional line and edge detection methods do not detect the PLs accurately due to the cluttered backgrounds while the more recent deep learning (DL) CNNs are also not feasible for efficient PL detection due to the coarse bounding boxes and the computationally expensive pixel-based segmentations. Hence, in this study we propose PLPose, a novel framework for detecting the PLs via key points-based pose estimation technique and adapt the MobileNetV3 CNN for this task (kMobileNetV3), by adding a simple key point detection head to predict the PL key points. We also introduce a novel data-centric architecture (kMobileNetV3 + UDP), by adding the unbiased data processing (UDP) module to our kMobileNetV3, for faster and more accurate key point-based PL detection along with novel methods for data annotations and performance evaluation. Evaluations of PLPose on three benchmark PL datasets (PLDM, PLDU and the Mendeley Powerline Dataset) reveal that our proposed framework outperforms the state-of-the-art top-down pose estimation networks (HRNet-w32, HRNet-w32 + UDP and Resnet-50 Simple Baselines) in processing speed (∼29 FPS) and model size (5.23 M) for PL detection. Thus, the comprehensive experimental results demonstrate the effectiveness of our proposed framework. Our code is available from Github (https://www.github.com/rubeea/pl_mmpose).

Leakage Current Detector and Warning System Integrated with Electric Meter

Electrical power is essential in human life. Thus, the security and reliability of its supply are of critical importance in a country’s industrial and economic development. The leakage and improper use of electricity may cause serious problems such as fire and electrocution. To prevent such incidents and minimize the loss of life and property, a leakage current detector and warning system are developed in this study. With a high-precision current transformer and high-gain linear converter, the detector effectively detects leakage current over 1 mA, which is validated in different methods. The detector can be integrated into widely used electric meters (Taipower Datong’s sub-meter model D4S) easily, and information on detected leakage current is transmitted to the cloud server through narrowband IoT wireless communication (NB-IoT) to warn users and management personnel of the electrical power line. The proposed detector and system are expected to prevent the fire caused by leakage current which was the main cause of the fire at homes and buildings and can be an effective means to manage the electrical powerline system and metering facilities.

A Physical Topology Identification Method for Low-voltage Distribution Areas Meter Box

This paper put forward a method on the premise of not changing the hardware circuit of the HPLC communication unit of the online electrical meter. In the HPLC communication unit of the electrical meter, the electrical meter address is modulated to the electric-power line through a high-speed carrier signal by the method of on-off keying. In the intelligent molded case circuit breaker of the meter box, after the new-type instrument transformer is used to extract the signal, the optimization algorithm is adopted to extract the electrical meter address to achieve physical topology identification of the meter box, forming a physical topographic map of low-voltage distribution area at the meter box level, which has the characteristics of low cost and high identification rate. This method is particularly suitable for the situation where HPLC communication units have been used in large quantities. Based on the current meter box operating method, it can effectively achieve the physical topology identification for the low-voltage distribution area, improve the physical topology identification rate for the meter box and reduce the identification cost.