Guaranteeing the trouble-free operation of capacitor banks in power-supply systems of industrial enterprises

The problem of resonance phenomena in power systems of industrial enterprises using capacitor banks for reactive power compensation was detected. Circuit of the capacitor banks tier to downshift main substation tires ispresent. But there is no common algorithm to calculate and avoid such trouble. The main goal of this article is to introduce some basics for power supply systems with possible resonant circuits engineering

Pathways to Electrochemical Solar-Hydrogen Technologies

Solar-powered electrochemical production of hydrogen through water electrolysis is an active and important research endeavor. However, technologies and roadmaps for implementation of this process do not exist. In this perspective paper, we describe potential pathways for solar-hydrogen technologies into the marketplace in the form of photoelectrochemical or photovoltaic-driven electrolysis devices and systems. We detail technical approaches for device and system architectures, economic drivers, societal perceptions, political impacts, technological challenges, and research opportunities. Implementation scenarios are broken down into short-term and long-term markets, and a specific technology roadmap is defined. In the short term, the only plausible economical option will be photovoltaic-driven electrolysis systems for niche applications. In the long term, electrochemical solar-hydrogen technologies could be deployed more broadly in energy markets but will require advances in the technology, significant cost reductions, and/or policy changes. Ultimately, a transition to a society that significantly relies on solar-hydrogen technologies will benefit from continued creativity and influence from the scientific community.Solid state NMR/Biophysical Organic Chemistr

Pathways to electrochemical solar hydrogen technologies

Solar powered electrochemical production of hydrogen through water electrolysis is an active and important research endeavor. However, technologies and roadmaps for implementation of this process do not exist. In this perspective paper, we describe potential pathways for solar hydrogen technologies into the marketplace in the form of photoelectrochemical or photovoltaic driven electrolysis devices and systems. We detail technical approaches for device and system architectures, economic drivers, societal perceptions, political impacts, technological challenges, and research opportunities. Implementation scenarios are broken down into short term and long term markets, and a specific technology roadmap is defined. In the short term, the only plausible economical option will be photovoltaic driven electrolysis systems for niche applications. In the long term, electrochemical solar hydrogen technologies could be deployed more broadly in energy markets but will require advances in the technology, significant cost reductions, and or policy changes. Ultimately, a transition to a society that significantly relies on solarhydrogen technologies will benefit from continued creativity and influence from the scientific communit

Roadmap on printable electronic materials for next-generation sensors

The dissemination of sensors is key to realizing a sustainable, ‘intelligent’ world, where everyday objects and environments are equipped with sensing capabilities to advance the sustainability and quality of our lives—e.g., via smart homes, smart cities, smart healthcare, smart logistics, Industry 4.0, and precision agriculture. The realization of the full potential of these applications critically depends on the availability of easy-to-make, low-cost sensor technologies. Sensors based on printable electronic materials offer the ideal platform: they can be fabricated through simple methods (e.g., printing and coating) and are compatible with high-throughput roll-to-roll processing. Moreover, printable electronic materials often allow the fabrication of sensors on flexible/stretchable/biodegradable substrates, thereby enabling the deployment of sensors in unconventional settings. Fulfilling the promise of printable electronic materials for sensing will require materials and device innovations to enhance their ability to transduce external stimuli—light, ionizing radiation, pressure, strain, force, temperature, gas, vapours, humidity, and other chemical and biological analytes. This Roadmap brings together the viewpoints of experts in various printable sensing materials—and devices thereof—to provide insights into the status and outlook of the field. Alongside recent materials and device innovations, the roadmap discusses the key outstanding challenges pertaining to each printable sensing technology. Finally, the Roadmap points to promising directions to overcome these challenges and thus enable ubiquitous sensing for a sustainable, ‘intelligent’ world

ЗАБЕЗПЕЧЕННЯ БЕЗАВАРІЙНОЇ РОБОТИ КОНДЕНСАТОРНИХ УСТАНОВОК В ЕЛЕКТРОПОСТАЧАЛЬНИХ СИСТЕМАХ ПРОМИСЛОВИХ ПІДПРИЄМСТВ

Purpose. The problem of resonance phenomena in power systems of industrial enterprises using capacitor banks for reactive power compensation was detected. Circuit of the capacitor banks tier to downshift main substation tires is present. But there is no common algorithm to calculate and avoid such trouble. The main goal of this article is to introduce some basics for power supply systems with possible resonant circuits engineering. Methodology. At the first step the data on the change of the current in the chemical company network when changing capacitor banks value are received. For these purposes the oscilloscope function of digital protection relay was used. Current data samples were analyzed by spectrum detection software. Most significant levels of the 3rd and 5th harmonics were achieved. Comparison of harmonic distortion levels with and without capacitor bank is given. Results. Achieved data allow making conclusion about overloading reasons of capacitor banks while higher harmonics currents presence. A voltage and current harmonious composition measuring in the absence of power quality analyzers using digital protection relay terminals or emergencies registers are proposed. The necessity of power quality monitoring near capacitor banks connections to avoid resonance phenomena (current and voltage resonance) in industrial power supply systems is proven. The control algorithm of capacitor banks to provide electromagnetic compatibility, while various modes of nonlinear load operation is given. Originality. Using of digital protection relay oscilloscoping for current resonant detection can allow to significally reduce time and cost of solution. Replacement parallel circuit comprising a branch and one active-inductive load to another branch network in the presence of higher harmonics source are proposed. Practical value. A sequence for measuring the levels of harmonic components at the connections of capacitor banks in the absence of specialized instruments is proposed. The algorithm to avoid possible resonance currents in the presence of condensing units is proposed.В статье рассматривается проблема резонансных явлений в системах электроснабжения промышленных предприятий, использующих конденсаторные установки для компенсации реактивной мощности. Приведены данные по изменению токов 3-й и 5-й гармонических составляющих в сети химического предприятия при изменении мощности присоединенных конденсаторных установок. Предложен способ измерения качества электроэнергии при отсутствии анализаторов. Разработан алгоритм обеспечения электромагнитной совместимости на присоединениях конденсаторных установок.У статті розглядається проблема резонансних явищ у системах електропостачання промислових підприємств, що використовують конденсаторні установки для компенсації реактивної потужності. Наведено дані щодо зміни струмів 3-ї та 5-ї гармонійних складових в мережі хімічного підприємства при зміні потужності приєднаних конденсаторних установок.  Запропонований спосіб вимірювання якості електроенергії в умовах відсутності аналізаторів. Розроблений  алгоритм забезпечення електромагнітної сумісності на приєднаннях  конденсаторних установок

Метод визначення параметрів еквівалентного асинхронного електродвигуна у реальному масштабі часу

A calculation of the parameters of the equivalent asynchronous electric machine allows introducing the automated calculation of the static and dynamic stability of an electrical supply system in an industrial enterprise for any combination of different electric motors. It also ensures the electromagnetic compatibility in a network by means of calculations of nonsinusoidal mode in the network with proposed sources of higher harmonics. The research purposeis a method for accurate determination of the equivalent asynchronous machine parameters for the load node consisting of several groups of asynchronous electric motors of the same type. An algorithm block diagram for calculating the initial data is developed. The input data is the number of groups of the same motortype, the number of machinesin each group,and a vector of the engine power ratings. The polling of the counters of each engine in all groups is performed through the use of an embedded cycle. A fragment of a substation one- line scheme which feeds an electrical industrial enterprise water circuit is given: three 800 kW asynchronous machines for each pump, three 400 kW asynchronous machines and three 250 kW asynchronous machines. The calculation results for the given example of the scheme are executed and presented in the table. The data obtained show that the actual parameters of the equivalent machine in a 6 kV load node are significantly different from the averaged data. The typical difference between the results obtained by the proposed method and the available methods is 5%, and the maximum reaches 30%.Therefore, it is expedient to use accurate data when performing calculations.Метою досліджень є розробка методу визначення у реальному часі параметрів еквівалентного асинхронного електродвигуна вузла навантаження, що складається з декількох груп однотипних асинхронних електродвигунів. Для проведення розрахунків був розроблений алгоритм, блок-схема якого наведена у публікації. Також наведені розрахункові формули, що враховують вагову долю кожного двигуна та їх групи на основі визначення та аналізу даних електроспоживання, отриманих з приладів обліку електроенергії, встановлених на приєднаннях електродвигунів. Для перевірки придатності розробленого алгоритму наведений розрахунок параметрів еквівалентної машини для вузла, який містить три групи двигунів (800, 400 та 250 кВт), по три двигуни в кожній групі. Одержані параметри еквівалентного асинхронного електродвигуна можуть бути використані для впровадження автоматизованої оцінки ефективності роботи групи однакових електродвигунів, розрахунків статичної та динамічної стійкості системи електропостачання промислового підприємства, визначення електромагнітної сумісності та захисту від резонансних явищ в мережі з джерелом вищих гармонік. Середнє значення різниці в відсотках між результатами, отриманими запропонованим методом і наявними методиками, становить 5%, а максимальне сягає 30%. Розроблений метод точного визначення еквівалентних параметрів асинхронного двигуна в режимі реального часу для вузла навантаження, що складається з декількох груп аналогічних АЕД, реалізується шляхом автоматичного визначення кількості робочих АЕД в кожній групі. Результати дослідження можуть бути використані для розрахунку ходу кожного двигуна. Пропонований спосіб визначення кількості робочих двигунів є кращим для визначення числа робочих синхронних двигунів в кожній групі однотипних двигунів

Pathways to electrochemical solar-hydrogen technologies

Solar-powered electrochemical production of hydrogen through water electrolysis is an active and important research endeavor. However, technologies and roadmaps for implementation of this process do not exist. In this perspective paper, we describe potential pathways for solar-hydrogen technologies into the marketplace in the form of photoelectrochemical or photovoltaic-driven electrolysis devices and systems. We detail technical approaches for device and system architectures, economic drivers, societal perceptions, political impacts, technological challenges, and research opportunities. Implementation scenarios are broken down into short-term and long-term markets, and a specific technology roadmap is defined. In the short term, the only plausible economical option will be photovoltaic-driven electrolysis systems for niche applications. In the long term, electrochemical solar-hydrogen technologies could be deployed more broadly in energy markets but will require advances in the technology, significant cost reductions, and/or policy changes. Ultimately, a transition to a society that significantly relies on solar-hydrogen technologies will benefit from continued creativity and influence from the scientific community

Roadmap on Printable Electronic Materials for Next-Generation Sensors

The dissemination of sensors is key to realizing a sustainable, 'intelligent' world, where everyday objects and environments are equipped with sensing capabilities to advance the sustainability and quality of our lives—e.g., via smart homes, smart cities, smart healthcare, smart logistics, Industry 4.0, and precision agriculture. The realization of the full potential of these applications critically depends on the availability of easy-to-make, low-cost sensor technologies. Sensors based on printable electronic materials offer the ideal platform: they can be fabricated through simple methods (e.g., printing and coating) and are compatible with high-throughput roll-to-roll processing. Moreover, printable electronic materials often allow the fabrication of sensors on flexible/stretchable/biodegradable substrates, thereby enabling the deployment of sensors in unconventional settings. Fulfilling the promise of printable electronic materials for sensing will require materials and device innovations to enhance their ability to transduce external stimuli—light, ionizing radiation, pressure, strain, force, temperature, gas, vapours, humidity, and other chemical and biological analytes. This Roadmap brings together the viewpoints of experts in various printable sensing materials—and devices thereof—to provide insights into the status and outlook of the field. Alongside recent materials and device innovations, the roadmap discusses the key outstanding challenges pertaining to each printable sensing technology. Finally, the Roadmap points to promising directions to overcome these challenges and thus enable ubiquitous sensing for a sustainable, 'intelligent' world