Determination of the input filter parameters of the active rectifier with a fixed modulation frequency

Goal. Development of a methodology for calculating the parameters of the active rectifier-voltage source input filter operating with a fixed modulation frequency to ensure electromagnetic compatibility with the supply network acceptable by standards at minimum values of the input inductance and checking its main characteristics on a mathematical model. Methodology. The authors have developed a methodology for calculating the parameters of the input filter of an active rectifier-voltage source. The calculation results are verified on the constructed mathematical model of a frequency converter, the scheme of which is an active rectifier and an autonomous voltage inverter. A series of experiments was carried out on a mathematical model to study the dependence of the total harmonic distortion of current and mains voltage on the value of the input inductance for various parameters of the input filter. Results. The structure and calculation procedure the input filter of an active rectifier operating with a fixed modulation frequency are proposed. The simulation results showed that the inclusion of a filter at the input of the active rectifier significantly improves its electromagnetic compatibility with the supply network in the entire range of variation of the input inductance of the circuit and makes it possible to achieve the values of the total harmonic distortion permissible by the norms. Originality. A structure and a calculation procedure the input filter of an active rectifier-voltage source operating with a fixed modulation frequency are proposed. Practical significance. The dependencies obtained in the article allow us to evaluate the relationship between the parameters of the filter elements and its characteristics among themselves and come to a compromise between them when designing a scheme for specific technical conditions.В статті запропоновано структуру та методику розрахунку вхідного фільтру активного випрямляча-джерела напруги, який працює з фіксованою частотою модуляції. Отримані залежності дозволяють оцінити взаємозв'язок параметрів елементів фільтра та його характеристик між собою та дійти компромісу між ними під час проектування схеми для конкретних технічних умов. Результати моделювання показали, що включення додаткового ланцюга RC фільтра на вході активного випрямляча істотно покращує його електромагнітну сумісність з мережею живлення у всьому діапазоні зміни вхідної індуктивності схеми та дозволяє досягати допустимих нормами значень сумарного коефіцієнту гармонічних спотворень

Эффективность работы активного управляемого выпрямителя в режиме искажения напряжения питающей сети

Goal. Checking the efficiency of the active rectifier with differences types of control systems in conditions of deep voltage distortions of a three-phase three-wire supply network. Methodology. The authors have used the Matlab/Simulink software environment to create a model of an active rectifier with various types of control systems as part of a frequency electric drive. We performed a series of simulations of the operating modes of an active rectifier with various control systems when the supply voltage is distorted. Results. When the active rectifier is operating in an unregulated mode, the distortions of the current and mains voltage exceed the maximum permissible values. The quality indicators of the mains current and mains voltage are significantly higher than the normally permissible values. In the absence of voltage distortions in the supply network, the operation of the active rectifier can effectively eliminate the distortions of the mains current, regardless of the type of control system of the active rectifier. In conditions of deep distortions of the supply network voltage, the operation of an active rectifier with a vector control system is more efficient than with a parametric control system. Originality. Criteria for determining the quality of consumed electricity at the connection point of the circuit are proposed. Practical significance. Recommendations have been developed for the use of active rectifier control systems when working with a distorted power supply voltage.Рассмотрена работа активного управляемого выпрямителя-источника напряжения (АВИН) с параметрической и векторной системами управления, работающих с фиксированной частотой модуляции в составе электропривода мощностью 315 кВт параллельно с другими нагрузками в условиях искажённого напряжения источника питания. Выполнено математическое моделирование АВИН с различными системами управления. Предложены критерии определения качества потребляемой электроэнергии в точке подключения схемы. Разработаны рекомендации по использованию систем управления АВИН при работе с искажённым напряжением источника питания

The efficiency of the active controlled rectifier operation in the mains voltage distortion mode

Goal. Checking the efficiency of the active rectifier with differences types of control systems in conditions of deep voltage distortions of a three-phase three-wire supply network. Methodology. The authors have used the Matlab/Simulink software environment to create a model of an active rectifier with various types of control systems as part of a frequency electric drive. We performed a series of simulations of the operating modes of an active rectifier with various control systems when the supply voltage is distorted. Results. When the active rectifier is operating in an unregulated mode, the distortions of the current and mains voltage exceed the maximum permissible values. The quality indicators of the mains current and mains voltage are significantly higher than the normally permissible values. In the absence of voltage distortions in the supply network, the operation of the active rectifier can effectively eliminate the distortions of the mains current, regardless of the type of control system of the active rectifier. In conditions of deep distortions of the supply network voltage, the operation of an active rectifier with a vector control system is more efficient than with a parametric control system. Originality. Criteria for determining the quality of consumed electricity at the connection point of the circuit are proposed. Practical significance. Recommendations have been developed for the use of active rectifier control systems when working with a distorted power supply voltage

Эффективность работы активного управляемого выпрямителя в режиме искажения напряжения питающей сети

Goal. Checking the efficiency of the active rectifier with differences types of control systems in conditions of deep voltage distortions of a three-phase three-wire supply network. Methodology. The authors have used the Matlab/Simulink software environment to create a model of an active rectifier with various types of control systems as part of a frequency electric drive. We performed a series of simulations of the operating modes of an active rectifier with various control systems when the supply voltage is distorted. Results. When the active rectifier is operating in an unregulated mode, the distortions of the current and mains voltage exceed the maximum permissible values. The quality indicators of the mains current and mains voltage are significantly higher than the normally permissible values. In the absence of voltage distortions in the supply network, the operation of the active rectifier can effectively eliminate the distortions of the mains current, regardless of the type of control system of the active rectifier. In conditions of deep distortions of the supply network voltage, the operation of an active rectifier with a vector control system is more efficient than with a parametric control system. Originality. Criteria for determining the quality of consumed electricity at the connection point of the circuit are proposed. Practical significance. Recommendations have been developed for the use of active rectifier control systems when working with a distorted power supply voltage.Рассмотрена работа активного управляемого выпрямителя-источника напряжения (АВИН) с параметрической и векторной системами управления, работающих с фиксированной частотой модуляции в составе электропривода мощностью 315 кВт параллельно с другими нагрузками в условиях искажённого напряжения источника питания. Выполнено математическое моделирование АВИН с различными системами управления. Предложены критерии определения качества потребляемой электроэнергии в точке подключения схемы. Разработаны рекомендации по использованию систем управления АВИН при работе с искажённым напряжением источника питания

Активний випрямляч з фіксованою частотою модуляції та векторною системою управління в режимі двонаправленого потоку енергії

Goal. Creation of a vector control system with improved characteristics for an active rectifier-voltage source operating in the bidirectional energy flow mode with a with a fixed modulation frequency. Methodology. The physical prerequisites for the active rectifier - voltage source operation in the system of a medium-power frequency electric drive are considered. A vector control system with a fixed modulation frequency is constructed, the principles of forming the signals acting in it and the influence on its operation of the converter power circuit parameters and the power consumed by it are considered. Mathematical modeling of the converter with the developed control system in MATLAB/Simulink made it possible to verify the correctness of the operation of the power circuit and the control system. Results. A new structure of a vector control system operating with a fixed modulation frequency is proposed, and the performance characteristics of the circuit in a wide range of changes in the magnitude and sign of the output power are obtained. The advantages of the new control system over the existing ones are shown. Originality. The physical prerequisites for the functioning of the power scheme and the vector control system of the ARVS proposed by the authors with a fixed frequency of modulation, the principles of forming the signals operating within it are considered in detail. Practical significance. New structure of the vector control system operating with a fixed modulation frequency is proposed and the advantages of the new control system over the existing ones are shown.В статті розглянуто роботу активного випрямляча-джерела напруги, що працює з фіксованою частотою модуляції в режимі двонаправленого потоку енергії, запропоновано нову структуру векторної системи управління, та отримано характеристики роботи схеми в широкому діапазоні зміни величини та знаку вихідної потужності. Розглянуті фізичні передумови функціонування силової схеми АВДН, запропонованої авторами векторної системи управління та принципи формування діючих усередині неї сигналів в складі частотного перетворювача середньої потужності. Показано переваги нової системи управління над існуючими та отримано залежності, що демонструють коректність застосування запропонованих у статті технічних рішень. Результати математичного моделювання показали, що АВДН, який працює з фіксованою частотою модуляції та запропонованою системою управління, дозволяє підтримувати задане значення вихідної напруги та близький до синусоїди струм мережі живлення при нульовому споживанні реактивної потужності в усталеному режимі в широкому діапазоні зміни параметрів схеми та величини і знаку потужності навантаження

РОЛЬ ГЕНЕРАЛІЗОВАНОЇ ВНУТРІШНЬОУТРОБНОЇ ІНФЕКЦІЇ У СТРУКТУРІ ПРИЧИН ЛЕТАЛЬНОСТІ ПЛОДІВ І НЕМОВЛЯТ У ВІННИЦЬКІЙ ОБЛАСТІ

The aim of the work – generalized intrauterine infection (GIUI) is the main cause of perinatal mortality (36 %) worldwide. According to data of the Ministry of Health, Ukraine,  intrauterine infection (IUI) is in second place among the causes of infant mortality, and its incidence rate reaches 40-70 %. The aim of our study was to evaluate the role of GIUI in the structure of causes of intrauterine fetus and infant fatality in Vinnytsia region for the period since 2013 to 2016 and analyze the preconditions that contributed to their development.Materials and methods.A retrospective, 626 protocols of autopsy of stillbirths and children who died in the first year of their life according to the data of  Vinnytsia Regional Pathology and Autopsy Bureau for  year 2013 to 2016 were analysed.Conclusions. GIUI is among the main causes of infant fatality and consists 25.3 % among the dead children. Among the main factors that aggravates the course of pregnancy and the condition of the fetus were chronic infectious diseases of the mother, inflammatory changes in the placenta. Multiple organ lesions and polietiology lesions in GIUI are factors that complicate on time in vivo clinical diagnosis, therefore in most of the cases, GIUI were posthumously diagnosed.Мета роботи – оцінити місце ГВУІ у структурі причин летальності плодів і немовлят у Вінницькій області за період з 2013 по 2016 роки та проаналізувати передумови, що сприяли їх розвитку.Матеріали і методи. Ретроспективно проаналізовано 626 протоколів розтину мертвонароджених і дітей, що померли на першому році життя, згідно з даними Вінницького обласного патологоанатомічного бюро за 2013-2016 рр. Висновки. ГВУІ є однією з основних причин летальності немовлят і складає 25,3 % серед загиблих дітей. Серед основних факторів, що обтяжують перебіг вагітності та стан плоду, є хронічні інфекційні захворювання з боку матері, запальні зміни плаценти. Поліорганність і поліетіологічність ураження при ГВУІ є факторами, що ускладнюють постановку своєчасного прижиттєвого клінічного діагнозу, тому в більшості випадків уточнені ГВУІ виставляються посмертно

Historical (1750 - 2014) anthropogenic emissions of reactive gases and aerosols from the Community Emission Data System (CEDS)

We present a new data set of annual historical (1750–2014) anthropogenic chemically reactive gases (CO, CH4, NH3, NOX, SO2, NMVOC), carbonaceous aerosols (BC and OC), and CO2 developed with the Community Emissions Database System (CEDS). We improve upon existing inventories with a more consistent and reproducible methodology applied to all emissions species, updated emission factors, and recent estimates through 2014. The data system relies on existing energy consumption data sets and regional and country-specific inventories to produce trends over recent decades. All emissions species are consistently estimated using the same activity data over all time periods. Emissions are provided on an annual basis at the level of country and sector and gridded with monthly seasonality. These estimates are comparable to, but generally slightly higher than, existing global inventories. Emissions over the most recent years are more uncertain, particularly in low- and middle-income regions where country-specific emission inventories are less available. Future work will involve refining and updating these emission estimates, estimating emissions uncertainty, and publication of the system as open source software

Gene-Environment Interaction Research and Transgenic Mouse Models of Alzheimer's Disease

The etiology of the sporadic form of Alzheimer's disease (AD) remains largely unknown. Recent evidence has suggested that gene-environment interactions (GxE) may play a crucial role in its development and progression. Whereas various susceptibility loci have been identified, like the apolipoprotein E4 allele, these cannot fully explain the increasing prevalence of AD observed with aging. In addition to such genetic risk factors, various environmental factors have been proposed to alter the risk of developing AD as well as to affect the rate of cognitive decline in AD patients. Nevertheless, aside from the independent effects of genetic and environmental risk factors, their synergistic participation in increasing the risk of developing AD has been sparsely investigated, even though evidence points towards such a direction. Advances in the genetic manipulation of mice, modeling various aspects of the AD pathology, have provided an excellent tool to dissect the effects of genes, environment, and their interactions. In this paper we present several environmental factors implicated in the etiology of AD that have been tested in transgenic animal models of the disease. The focus lies on the concept of GxE and its importance in a multifactorial disease like AD. Additionally, possible mediating mechanisms and future challenges are discussed

Methodology of Application of Modern Educational Technologies for Training Specialists

This paper discusses the methodology of applying modern educational technologies for training specialists in the field of metallurgical production based on the CDIO initiative. In order to expand the possibilities of the practice-orientedness of specialists, practical training is used to solve real problems and conditions of enterprise activity with the help of applied and specialized software products and the project method. The organizational and structural principles of the project method implementation are shown.В данной работе рассмотрена методология применения современных образовательных технологий для подготовки специалистов в сфере металлургического производства на основе инициативы CDIO. С целью расширения возможностей практико-ориентированности специалистов применяется практическая подготовка для решения реальных проблем и условий деятельности предприятий с помощью прикладных и специализированных программных продуктов и метода проектов. Показаны организационный и структурный принципы реализации метода проектов

New national and regional bryophyte records, 59

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