Current Transformer Research Articles

Intelligent pointing increases the fraction of cloud-free CO2 and CH4 observations from space

For most CO2 and CH4 satellites, only a small percentage (∼10%) of observations yield successful retrievals, with the remaining ∼90% rejected, primarily due to the effects of clouds. Discarding this large fraction of data is an inefficient strategy worth reconsidering due to the costs involved in developing, launching and operating the satellites to make these observations. However, if real-time cloud data are available together with pointing capability, cloud data can guide the instrument pointing in an “intelligent pointing” strategy for cloud avoidance. In this work, multiple intelligent pointing simulations were conducted, demonstrating the significant advantages of this approach for satellites in a highly elliptical orbit (HEO), from which nearly the whole Earth disk can be observed. Multiple factors are shown to contribute to intelligent pointing efficiency such as the size and shape (or aspect ratio) of the field of view (FOV). For the current baseline orbit and Imaging Fourier Transform Spectrometer (IFTS) observing characteristics for the proposed Arctic Observing Mission (AOM), the monthly fraction of cloud-free observations is roughly a factor of 2 (ranging from ∼1.5–2.5) more than obtained with standard pointing (in which cloud information is not used). A similar efficiency is expected in a geostationary orbit (GEO) with an IFTS, however, for a dispersive instrument in HEO or GEO, the gain is more modest. This result is primarily attributed to the ∼1:1 aspect ratio of the IFTS FOV, since it is more efficient for cloud avoidance and scanning irregularly-shaped land masses than the long and narrow slit projection of a typical dispersive spectrometer. These results have implications for the design of future CO2 or CH4 monitoring satellites and constellation architectures, as well as other fields of satellite earth observation in which clouds significantly impact observations.

Partial discharge diagnostics on inverter-fed drives of electric vehicles

In this paper, the possibilities of partial discharge measurement at square-wave voltages are discussed. The focus is on low-voltage machines, such as those used in electric vehicles. An insight into common measurement methods is given. In this work, high-frequency current transformers and near-field probes are used as sensors. The generation of a realistic steep-edged test voltage according to IEC/TS 61934 is also discussed and demonstrated on an inverter with silicon carbide semiconductors.Experiments are conducted to compare the sensors used. A direct comparison between cable-based sensors (HFCT) and antennas (near-field probes) is provided. Resonance points to open motor windings according to IEC/TS 60034-27‑5 and their significance for partial discharge measurement are also investigated. The results show that the high-frequency current transformers and the ball probe are able to detect PD even at steep voltage edges. Excitation with a fast voltage edge results in non-negligible overshoots in the overall system due to resonances. It can be shown that the partial discharges occur during these overvoltages.

The consequences of informal employment on workers’ health and family well-being in Europe

Abstract Introduction Informal employment, characterized by unregistered and unprotected employment arrangements, can be detrimental to the health and well-being of workers and their families. Because non-standard work with ambiguous employment arrangements is growing more common across Europe, informal employment is becoming a health risk for an increasing number of people. The aim of this study is to explore the link between informal employment and health, focusing on the effect of employment precariousness and accounting for macrostructural contextual factors. Methods A sample of workers aged 15-64 in Europe from the latest European Working Conditions Survey of 2021, will be used. Using logistic regression models, with standard employment as the reference, the consequences of informal employment on physical health, psychosocial health, and family well-being will be assessed. The effects of precarious conditions (employment insecurity, low material rewards, lack of rights and opportunities, and disempowerment) on the relationship will be tested. Results Based on existing theory, the results should reveal that informal employment is associated with adverse outcomes. Precarious employment conditions should have a stronger effect for informal workers and their families as opposed to workers in standard employment. The results will be analyzed in relation to country-based structural factors such as welfare state policies and labour market trends. Conclusions The study will have implications for both research and policy. It will fill a critical research gap of the underexplored association between informal employment, workers’ health, and family well-being. Since non-standard work is growing in the European countries, the results should also demonstrate the importance of targeted policies to reduce the negative effect of this type of work to protect the health of not only workers, but the well-being of their families. Key messages • Informal employment is associated with adverse outcomes among workers and their families. • Employment precariousness is key to explaining how informality determines health and should therefore be at the core when adapting policies to the current labour market transformations.

Evaluation of the Optional Wideband Accuracy of Inductive Current Transformers in Accordance with the Standard IEC 61869-1 Ed.2

This paper presents the evaluation of tested inductive CTs’ accuracy for distorted current harmonics in accordance with the optional accuracy class WB1 introduced by the new edition of the standard IEC 61869-1 published in the year 2023. The tests were performed in compliance with the interpretation sheet IEC 61869-2:2012/ISH1:2022. Therefore, the resistive and the resistive–inductive loads of the secondary winding of tested inductive CTs were used, as this was required for the given test conditions. The results indicate that the units designed for the transformation of a sinusoidal current of a frequency of 50 Hz ensure the high wideband transformation accuracy of the distorted current harmonics, as demanded by the power quality monitoring and distorted electrical power and energy requirements. The key to this is proper design using modern magnetic material(s) for the magnetic core and its oversizing in relation to the requirements for a given accuracy class defined for the transformation of sinusoidal currents with a rated frequency. Both tested inductive CTs with a rated primary current RMS value equal to 300 A, class 0.2 and 0.5, ensured compliance with the requirements of the WB1 wideband accuracy class.

Zero-Voltage Ride-Through Scheme of PMSG Wind Power System Based on NLESO and GFTSMC

In this paper, a scheme for zero-voltage ride through of a permanent magnet synchronous generator wind power system is proposed. Maintaining the stability of DC-link voltage is the key to realizing zero-voltage ride through. A braking chopper is used to dissipate the active power to restrain the rise of DC-link voltage during a grid fault. However, the braking chopper-caused disturbance to the double closed-loop control of the grid side converter makes the control effect on DC-link voltage worse. Therefore, a robust current feedforward control, based on a nonlinear extended state observer and global fast terminal sliding mode control is proposed. A nonlinear extended state observer estimates the total disturbance in the system and compensates for the control law. Global fast terminal sliding mode control enables the system to reach the sliding mode surface in a finite time, and its control law is continuous without switching terms, thereby eliminating the chattering phenomenon. A nonlinear extended state observer and global fast terminal sliding mode control change the current feedforward control into a nonlinear robust current feedforward control. The control effect is improved, and the use of current transformers is reduced in practical applications, thereby reducing costs. The validity of this scheme has been verified by simulation.

Remanent flux detection method for a protection current transformer based on fluxgate theory

Protection current transformer (CT) saturation caused by the remanent flux will affect the performance of protective relays. The saturation can be suppressed by demagnetizing the iron core. Detecting remanent flux can make demagnetization more effective. This paper proposes a remanent flux detection method based on the fluxgate theory, which can effectively measure the magnitude and polarity of the remanent flux using the second harmonic of the current generated by a single-phase electronic inverter. The proposed method can detect the remanent flux without changing it, no matter whether the CT is connected to the power system or not, which means that this method can measure the remanent flux when the CT is under normal operating conditions. The effectiveness of this method is verified in EMTP-RV software, and the simulation results show that this method can detect the remanent flux with high accuracy.

Implementation of a Real-Time IoT Based Energy Management System

Energy Management System has received a lot of attention from both academia and industries due to the rate of energy consumed by electrical appliances. These industries are faced with inflation in the cost of electrical bills. Therefore, this study presents the design and implementation of a real-time IoT based Energy Management System (EMS) to reduce the inflation in the cost of these electrical bills. The system comprises four (4) basic units namely; the sensing unit, control unit, display unit and switching unit. The sensing unit comprises of two sensors namely; Current Transformer (CT) sensor and voltage sensor which senses and measures the parameters (voltage and current) and sends the parameters to the control unit. This control unit comprises two (2) microcontrollers namely; Arduino Nano and ESP32. The Arduino Nano processes the received data from the sensing unit and sends the processed data to the display unit and ESP32 microcontroller for real-time monitoring. In addition, the ESP32 microcontroller sends the processed data to the cloud. Furthermore, the web-based application receives the measured parameters from the cloud and thus, allowing the user to monitor as well as control the rate of energy consumption of electrical appliances. The experimental results obtained showed that the developed system efficiently monitors and control the rate of energy consumption of the three applied loads (Edison 2.7 bulb, standing fan and phone charger). Hence, reduces the cost of electrical bills consumed by these appliances.

ФОРМУВАННЯ ТА ТРАНСФОРМАЦІЯ ЗЕЛЕНОЇ ІНФРАСТРУКТУРИ ЖИТЛОВОГО РАЙОНУ ТАЇРОВА, М. ОДЕСА, УКРАЇНА

The article examines the historical formation of Odesa and the Tairov residential area, as well as architectural and urban planning solutions for green infrastructure of the Soviet period, and demonstrates a project proposal for a functional and planning system of green spaces of Soviet urban planning in the Tairov area. The current state and transformation of green spaces and how they affect the social aspect of residents are revealed. The analysis of the planned master plans and existing buildings allows us to conclude that, unlike the Cheremushky district, many of the plans were not implemented during the construction of the Tairova settlement, namely: green boulevards within microdistricts, courtyard solutions and landscaping, series and configurations of residential buildings on individual plots. The main feature of a high-quality green space system is the creation of comfortable living and recreational conditions for the population. The basis for obtaining a high-quality living environment is compliance with established architectural, planning, sanitary and engineering recommendations and standards that regulate the general functional and compositional solutions, location of green, blue, transport and pedestrian, and social infrastructure. In the process of urban development, green areas have traditionally been aimed at improving sanitary conditions for residents. They helped clean the air from harmful substances and provided places for recreation. Properly planned green areas make an important contribution to the aesthetic appearance of the neighborhood and create psychological comfort for residents. The main problems of the green network, which were identified in the process of transformation of the Tairova district, are outlined.

Deterioration identification method of key optical devices of fiber optical current transformer based on neural network

AbstractOptical fiber current transformers (FOCTs) are affected by various external factors, resulting in the deterioration or even failure of devices, causing changes in critical state quantities, and reducing the accuracy and reliability of products. To solve this problem, based on the neural network algorithm, this paper starts from the four deterioration characteristics of FOCT SLD junction temperature, SLD output optical power, phase modulator half‐wave voltage, and optical fiber sensing ring temperature, and identifies the deterioration of key optical components of FOCT, which provides a basic model and data support for the online monitoring and early warning to improving the stability and reliability of FOCT in long‐term operation.

Показатели и рейтинги в глобальном управлении: новые тенденции

Numerous indicators and ratings aimed at assessing and comparing states based on different criteria, such as volume of gross domestic product (GDP), freedom of speech, gender equality, or attractiveness of local cuisine, have become an integral part of contemporary communications and international relations. Country rankings can be used as a basis for agenda setting, political influence, or developing approaches to global governance. National governments sometimes use rankings developed by international intergovernmental and non-governmental organizations, or in some cases by business entities, as benchmarks for their countriesʼ development and national scorecards and indexes. Or, if the ratings are considered unsatisfactory, governments can distance themselves from such reports, accusing their authors of political bias. Lately, the phenomena of international indicators and ratings, the principles behind their development, and their influence and usage in the context of global governance have attracted attention of researchers specializing in international relations and other social science disciplines. This article examines different theoretical approaches to analyzing the phenomena of indexes and ratings and provides evaluation of the phenomena. The author focuses on the premises for the increasing interest in comparative approaches and emergence of newly developed ratings and indexes, highlights limitations and weaknesses of such approaches, and examines new trends in the field and possible scenarios of its future development in the context of current global transformations.

Twins transformer: Cross-attention based two-branch transformer network for rotating bearing fault diagnosis

Due to the inherent shortcomings of traditional depth models, the Transformer model based on the self-attention mechanism has become popular in the field of fault diagnosis. The current Transformer's self-attentive mechanism provides an alternative way of thinking, which can make direct association between each signal. However, it can only focus on the association information within a sequence, and it is difficult to understand the information gap between samples. Therefore, this paper proposes the two-branch Twins attention, which for the first time uses cross-attention to focus on information associations between samples. Twins attention uses cross-attention to learn information associations between samples in addition to retaining the information associations within sequences learned by self-attention. The performance of the proposed model was validated on four popular bearing datasets. Compared to the original transformer structure, the average accuracy of each dataset improved by 1.73% to 99.42%, leading the noise experiments.

A complex perspective on digital education development: From economic impact to community advancement

Evidence shows that education prepares future generations for the future, but technological innovations are reshaping the present and the near future to such an extent that it is increasingly unpredictable what exactly future generations should be prepared for. The research was guided by Microsoft's 2018 research summary "Transforming education - Empowering the students of today to create the world of tomorrow", which provided inspiration on the most common mistakes and how to avoid them.
 The first part of the paper reviews the societal drivers and imperatives for transforming education through a complex literature review, while the second part of the paper presents a practical organisational transformation process sequence. The paper presents Hungarian examples and cases, but it can also serve as a thought-provoking tool for the wider region, where the study of the process outlined reveals a striking contrast between potential and current transformation efforts. The purchase of technological equipment and the provision of schools with new educational technology is not achieving the desired objective, as the funds are not available. It is instructive to reflect on what the system developers have tried to skip over and get away with, and why this is not a viable path.

Using data to understand neurology services

Data, information and research are key to understanding health services and identifying areas for improvement. Without reliable, up-to-date data on activity, outcomes and spending, health and care services cannot be effectively monitored and held to account. Sue Thomas and George Lawton outline how data is currently used, giving examples of how one type of data, Hospital Episode Statistics, can be used. The current transformation of NHS services will require everyone to be data aware. In neurology, the launch of a new online national adult neurology data dashboard will support integrated care boards (ICBs) to monitor key neurological conditions. This is one of the ICB tools being developed for the NHS neurology transformation agenda, which will raise greater awareness of the need for ICBs to ensure neurology has a much greater profile in the future.

Manganese-Based Nanotheranostics for Magnetic Resonance Imaging-Mediated Precise Cancer Management.

Manganese (Mn)-based magnetic resonance imaging (MRI) has become a competitive imaging modality for cancer diagnosis due to its advantages of non-invasiveness, high resolution and excellent biocompatibility. In recent years, a variety of Mn contrast agents based on different material systems have been synthesized, and a series of multi-purpose Mn nanocomposites have also emerged, showing satisfactory relaxation efficiency and MRI performance thus possess the transformation and application value in MRI-synergized cancer diagnosis and treatment. This tutorial review starts from the classification and properties of Mn-based nanomaterials, and then summarizes various preparation and functionalization strategies of nanosized Mn contrast agents, especially focuses on the latest progress of Mn contrast agents in MRI-synergized precise cancer theranostics. In addition, present review also discusses the current clinical transformation obstacles such as unclear molecular mechanisms, potential nanotoxicity, and scale production constraints. This paper provides evidence-based recommendations about the future prospects of multifunctional nanoplatforms, as well as technical guidance and panoramic expectations for the design of clinically meaningful cancer management programs.

Social Movements in Europe, from the Past to the Present

Abstract Over time, the concept of social movement has evolved as society has changed, but has always implied collective action in the public space. The form of social contestation has changed, according to the conjuncture of each historical period. In 18th century, the transition from the Old Regime to Liberalism provoked movements considered by some authors as “primitive” or “premodern”, as they were spontaneous, sporadic and depoliticized. Industrial society of the 19th century gave rise to the labor movement and trade unionism, which from then on organized the social movements. In the 20th century there were changes and innovation in the collective way of acting, there was the emergence of a series of social movements that differ from the traditional in terms of the objectives and actors involved, such as the pacifist, ecologist, feminist movements, acting on the fringes of parties and unions. The 21st century has witnessed a set of movements that begin on social networks, such as Generation Scratch, Outraged, Occupy Wall Street, Screw the Troika, and quickly outgrow local scales to become global. Through the use of a theoretical and conceptual framework derived from the theories of social movements and taking into account the current transformation of collective action that has been witnessed in the 21st century, we intend to verify if we are facing a new social phenomenon or another phase of “repertoire” change.

Line electrical transmission damage identification tool in distributors electrical networks

In the paper showing that one of the main way for Ukraine electric power industry evolution is electric power networks and systems improvement and construction considering Smart Grid concept. The main idea of Smart grid is the reliable, energy-efficient and high-quality energy supply system. To implement the idea, it is necessary to create a high-performance information and computing infrastructure. The main components of Smart Grid is emergency mode diagnostics and damage monitoring. Providing fault diagnostics and fault monitoring can improve the power supply reliability and quality to consumers. So, the task of quickly and accurately determining the place of damage is important. In the article showing that emergency detection tools in sections of both cable and overhead electrical networks it’s a way to improve efficiency of the networks. The diagram of the placement of damage indicators on the section of the electrical distribution network is presented, which allows determining the direction of the search for the location of the damage. A comparative analysis of measuring current transformers of optical and electromagnetic type was carried out. It is shown that a significant number of advantages of optical measuring current transformers, which can be used in damage indicators, can be provided by measuring current transformers of the electromagnetic type. Creating fault indicator based on the Smart Grid concept lets do to reduce searching time for the cause and location of an emergency situation to a minimum. In this concept application fault indicator in energy grid ensure it connection to operating overhead and cable lines without removing voltage by connecting the output of the secondary winding of the measuring current transformer of the detachable design to the measuring converters directly placed near the current measuring transformers with the help of a mechanical spring fastener. A block diagram of a specialized information-measuring system with a damage indicator was created, taking into account the requirements of the Smart Grid concept, which allows to reduce the time of searching for the cause to a minimum.

Interference on Static Energy Meters Resulting From Droop of the Current Transformer

Interference on Static Energy Meters Resulting From Droop of the Current Transformer

Альтернативная ресурсосберегающая дифференциальная защита электродвигателей

The author presents the principle of operation of alternative resource-saving differential protection for high-voltage electric motors, made with adjustable selection of settings, without the use of measuring current transformers (CT) and current relays with ferromagnetic cores, which have significant weight and dimensional parameters and high cost. The result is the creation of resource-saving protection for the protection of electric motors, made on inductive coils and reed switches. Protections with their application can be used as an alternative to the traditional protections of electric motors made on electromechanical, semiconductor and microprocessor bases and at the same time by their characteristics are not inferior to them. The scientific novelty is that this protection has the effect of resource saving of used materials, thus allowing to realize significant savings of copper and steel, and represents a new approach in realization of differential protection for electric motors. All structural elements of the presented protection are made of heat-resistant, durable and lightweight plastic, type «PLA», printed on a 3D printer. The resource-saving of these protections is in the use of inductance coils and reed switches, which are, both in terms of their cost and weight and dimensional parameters, an order of magnitude cheaper and smaller in size and weight than the above-mentioned measuring CTs. The use of the presented protection increases the reliability of relay protection, both the cell itself, where it is installed, and the electrical installation, which is an electric motor connected to it. The proposed differential protection is made in the form of a structure with the installation of its elements inside the cell of complete (closed) switchgear voltage 6-35kV and in the electric motor

Technical Infrastructure for Clinical Translation of Electron FLASH

For safe clinical translation of electron FLASH, hardware tools for real-time beam control and software tools for treatment planning are necessary. The purpose of this study is to prototype high-throughput hardware for real-time beam control, along with accurate beam modeling of a modern clinical Linac configured to deliver FLASH dose-rates. For real-time beam current monitoring, a beam current transformer (BCT) was initially coupled to a fast digitizer and its linearity was established by varying dose per pulse. The radiation pulse width was modified, and this change was measured using the BCT. The BCT was then used to measure the variability of dose per pulse and pulse width due to a mistuned linear accelerator system. Next, the BCT was interfaced with a field programmable gate array (FPGA) which provides the ability for high-throughput and deterministic control of the Linac based on dose accumulation. For beam modeling, the program, TOol for PArticle Simulation (TOPAS), was used to obtain beam parameters by using Bayesian optimization of the beam energy, source size, angular, and energy spread via comparison of simulated and representative dose profiles. The beam model would then be employed to calculate 3D dose distribution in a CT scan of a 3D-printed anatomically realistic mouse phantom. The area under the current-time curve from the BCT exhibited excellent linearity (response = 12.80 nC/Gy) up to 2.5 Gy/Pulse (R2 = 0.99). The peak beam current for the electron FLASH beam was measured to be ∼10 mA for an instantaneous dose-rate of ∼5×105 Gy/s. The measured radiation pulse width agreed with the expected value (3.7 μs). The pulse width was then shortened and the measurement by the BCT indicated pulse widths of 1.8 μs and 0.5 μs corresponding to 0.7 Gy/pulse and 0.3 Gy/pulse, respectively. The beamline exhibited a ramp-up in dose per pulse and pulse width when using the automatic frequency controller (AFC). For the first pulse, the dose delivered was ∼0.1-0.3 Gy and the pulse width was 0.6 μs. The output stabilized to nominal values of dose and pulse width after 3-4 pulses. This ramp-up was mitigated by manually tuning the RF resonance with the AFC disabled, after which the BCT exhibited constant output and pulse width. The beam modeling work is in progress. We demonstrated that a BCT can provide real-time measurement of per-pulse output suitable as input for FLASH beam control based on dose accumulation. The next steps are to quantify the accuracy of the dose control mechanism with the FPGA-based hardware. Potential failure modes will be identified and mitigated in parallel with the development of the hardware. A 3D-printed mouse phantom has been constructed to facilitate beam modeling work for treatment planning (in progress). On completion of this work, it is expected that we will have key infrastructure elements needed to move towards an eventual FDA investigational device exemption for clinical trials.

Architectural form: the space of experience and technological innovations in construction

The research work aims at revealing the purely immanent foundations of the systemic knowledge of architectural form, which initially always has an instrumentalist character. In the context of current transformations in the field of science in general and the attitude of society to it, the differentiation of theoretical fundamental layer of knowledge and applied knowledge has become extremely complicated. At the same time, the very need to clarify the root foundations of architecture not only persists as a criterion and sign of academic identity, but also sounds quite certain in relation to the search for possible scenarios of future development of this branch of human activity, production, social exchange, information flows, and reorganization of the living environment. This search is connected most directly to the reflections on the processes of architectural form generation. The issue of architecture’s future is the problem of finding a new architectural form. A group of factors, including the use and experimentation with new building materials and technologies, is not excluded from this search, but does not exhaust the strategy of form generation. The proposed exposition of architectural form in the context of modern technological innovations relies mostly on a historical cross-section of the architectural component of human culture. In other words, it is a study into the foundations of the methodology of the science of architecture including three basic points: 1) the science of architecture is its understanding as an autonomous reality; 2) this understanding may only be achieved by revealing the immanent logic of historical development; 3) architecture in its sovereignty as an existential "region" or a phenomenon of human civilization is expressed essentially in the form, the structural analytics of which crystallizes the universal logical and semantic dimension of the evolution of architectural reality.