Research of various inductors configurations for heating titanium slabs

In this paper various inductors configurations for heating a titanium slab, as well as the influence of frequency changes on efficiency of inductors are considered. The calculations are carried out by means of finite element method. In this research a three-dimensional time-harmonic model in A-formulation of Maxwell's equations is used. In the framework of this work, only electromagnetic problem was calculated, since the main aim of this work is to assess the effectiveness of inductor configurations in terms of electromagnetic problem. Efficiency of inductor and the uniformity coefficient introduced herein have been chosen as the comparison parameters. Ultimately, distribution of electromagnetic power density in the workpiece is shown, also conclusions are drawn for each of inductor configurations. © Published under licence by IOP Publishing Ltd

Risk for human tick-borne encephalitis, borrelioses, and double infection in the pre-Ural region of Russia.

We assessed the risk for human tick-borne encephalitis (TBE), ixodid tick-borne borrelioses, and double infection from 1994 to 1998 in Perm, which has among the highest rates of reported cases in Russia. We studied 3,473 unfed adult Ixodes persulcatus ticks collected from vegetation in natural foci and 62,816 ticks removed from humans. TBE virus and Borrelia may coexist in ticks

Direct measurement of the current and power in the load loop of high -frequency electrotechnological devices using the Rogovsky coil

The article describes the power supply system of induction furnace based on a semiconductor converter, in which it is possible to work simultaneously in the exciting mode of low-frequency currents and frequencies three times higher when switching the compensation circuit of the furnace inductor at different stages of metal melting. Calculations of electromagnetic processes have shown the advisability of operating the power supply system in the mode of tripling the current frequency at the stage of heating and melting of the metal, but in the mode of low frequency - at the stage of technological processing of the melt. The ratio between the parameters of the furnace power supply in various operating modes are established. © Published under licence by IOP Publishing Ltd

Research of a dual-frequency power supply system for induction crucible furnaces for melting ferrous and non-ferrous metals

The article describes the power supply system of induction furnace based on a semiconductor converter, in which it is possible to work simultaneously in the exciting mode of low-frequency currents and frequencies three times higher when switching the compensation circuit of the furnace inductor at different stages of metal melting. Calculations of electromagnetic processes have shown the advisability of operating the power supply system in the mode of tripling the current frequency at the stage of heating and melting of the metal, but in the mode of low frequency - at the stage of technological processing of the melt. The ratio between the parameters of the furnace power supply in various operating modes are established. © Published under licence by IOP Publishing Ltd

Review of Research on the Theme: Management of the Arc Position in Arc Vacuum Furnaces

In this paper, a review of research on the topic: control of the position of the arc in an arc vacuum furnace is conducted. Existing theories, various calculation methods with experimental confirmations are considered.В данной работе проведен обзор исследований по теме: управление положением дуги в дуговой вакуумной печи. Рассмотрены существующие теории, различные методы расчета с экспериментальными подтверждениями

Power quality problems and ways of modeling the electrotechnological installations for identification of negative phenomena and factors arising from the operation of this equipment

Статья описывает проблему снижения качества электроэнергии, возникающую в процессе наращивания энергетических мощностей. Снижение качества электроэнергии может быть вызвано множеством различных факторов, проявляющихся при определенных обстоятельствах, и имеют поэтому разные решения по их устранению. Наиболее остро стоит проблема влияния качества электроэнергии на энергетические параметры электрооборудования и электроприемников в металлургической отрасли и в области механической обработки, широко эксплуатирующих различные электротехнологические установки. Важным элементом при подготовке специалистов в области электроэнергетики и электротехники является формирование компетенций, направленных на выявление и устранение причин, вызывающих снижение качества электроэнергии. Наиболее эффективно эти компетенции могут быть сформированы при выполнении действий на реальном оборудовании или на физической модели.The article describes the problem of reducing power quality, arising in the process of building energy capacity. Reduced power quality can be caused by many different factors, manifested in certain circumstances, and therefore have different solutions for their elimination. The most acute problem of the influence of power quality parameters on energy and electrical power consumers in the steel industry and in the field of machining, widely different operating electrotechnological installation. An important element in the preparation of specialists in the field of electricity and electrical engineering is the formation of competences, aimed at identifying and eliminating the causes of decline in power quality. The most effective of these competencies can be formed when performing actions on real hardware or on a physical model

REVIEW OF THE METHODS OF INCREASING THE ELECTROLYSIS INSTALLATIONS EFFICIENCY FOR PRODUCTION OF HYDROGEN BY ALKALI METHOD

The paper analyzes the experimental work to improve the electrolysis installations efficiency for the production of hydrogen by the alkaline method. The main promising physical methods studied in foreign laboratories are shown. The conclusion about the prospects of upgrading existing installations is made.В работе проведен анализ экспериментальных работ по повышению эффективности электролизных установок для производства водорода щелочным способом. Показаны основные перспективные физические способы, исследуемые в зарубежных лабораториях. Сделан вывод о перспективности модернизации существующих установок

Application compensating devices and resonant filters to suppress the voltage higher harmonics in the electric grid

В статье обосновывается целесообразность применения компенсирующих устройств, в том числе конденсаторных батарей и резонансных фильтров высших гармоник. Описаны особенности применения данных устройств при комплексном использовании. Описана схема разработанных фильтров, приведены результаты сравнения применяемых компенсирующих устройств. Проведены расчеты по нахождению величин тока основной гармоники нагрузки и фильтра.The article proves the feasibility of compensating devices, including capacitor banks and harmonic filter resonance. The features of the application of these devices with the integrated use. The scheme developed by the filters, given the results of comparison used compensating devices. The calculations for finding the values of the fundamental harmonic current load and filter

Development intellectual of laboratory for trainees on electrical engineering courses

Проведение лабораторных практикумов является существенным этапом подготовки специалистов любого профиля. В настоящее время многими производителями предлагаются лабораторные стенды, отвечающие широкому спектру изучаемых дисциплин, как общего профиля, так и специализированных, однако охватить обширную тематику вопросов обсуждаемых в рамках дисциплин электроэнергетического профиля достаточно сложно. Некоторые вопросы специальных дисциплин требуют более пристального внимания, чем сейчас, что объясняет потребность в разработке специализированных лабораторных стендов для этих дисциплин.The article explains the usefulness of agents of low-power synchronous machines based on the current source. The features of low power characteristics of synchronous machines. Be described a functional block diagram of the excitation system, which allows to regulate the amount of current. Described technological features of the scheme, presented the benefits of such a scheme with respect to traditional systems

DEVELOPMENT OF PHYSICAL MODEL OF VACUUM ARC GARNING FURNACE

In this paper, we investigated the possibility of creating a physical model of a vacuum arc skull oven based on similarity criteria calculated for a real object, which make it possible to approximate the characteristics under study to a large-sized stove to find ways to reduce energy costs.В работе исследована возможность создания физической модели вакуумной дуговой гарнисажной печи на основе рассчитанных для реального объекта критериев подобия, позволяющих аппроксимировать исследуемые характеристики на крупногабаритную печь для поиска возможностей снижения энергозатрат