AUTOR DO BLOG ENG.ARMANDO CAVERO MIRANDA SÃO PAULO BRASIL

"OBRIGADO DEUS PELA VIDA,PELA MINHA FAMILIA,PELO TRABALHO,PELO PÃO DE CADA DIA,PROTEGENOS DO MAL"

"OBRIGADO DEUS PELA VIDA,PELA MINHA FAMILIA,PELO TRABALHO,PELO PÃO DE CADA DIA,PROTEGENOS  DO MAL"

“SE SEUS PROJETOS FOREM PARA UM ANO,SEMEIE O GRÂO.SE FOREM PARA DEZ ANOS,PLANTE UMA ÁRVORE.SE FOREM PARA CEM ANOS,EDUQUE O POVO.”

“Sixty years ago I knew everything; now I know nothing; education is a progressive discovery of our own ignorance. Will Durant”

quarta-feira, 2 de junho de 2021

Ruggedness of High-Voltage IGBTs and Protection Solutions by Thomas Basler Approved to obtain the degree of Doctor of Engineer. Technical University of Chemnitz


 Ruggedness of High-Voltage IGBTs and Protection Solutions by Thomas Basler Approved to obtain the degree of Doctor of Engineer. Technical University of Chemnitz 

Bibliographic information from the German National Library 
The German National Library lists this publication in the German National 
Bibliography; detailed bibliographical information is in the Available on the Internet at http://dnb.d-nb.de. 
This work was supported by the Faculty of Electrical Engineering and Information technology from the Technical University of Chemnitz as a dissertation Approved to obtain the degree of Doctor of Engineer. The work was written in English. Date of submission: September 10, 2013 Reviewer: Prof. Dr. Josef Lutz Prof. Dr. Steffen Bernet Dr. Roland Jakob Defense Day: February 28, 2014

ABSTRACT
Application-Oriented IGBT Requirements and Motivation of this Work

 This thesis was written at Chemnitz University of Technology in cooperation with General Electric Energy Power Conversion GmbH, former Converteam, in Berlin. Many of the tasks and problem-settings regarding the improvement of ruggedness of high-voltage IGBTs were derived directly from the industry partner and its 3-level medium-voltage converter application. This topology is widely used for industrial and traction applications [Ber00]. For the considered converter, 42-chip press-pack IGBTs with a voltage rating of 4.5 kV are used. The challenge was to investigate all possible IGBT short-circuit cases in this type of converter and to shift the complete converter protection concept to the optimum level. The interconnection between the gate unit and the IGBT and the surrounding circuit parameters like the stray and shortcircuit inductance were of special interest. In addition to the short-circuit topic, a solution should be found on how to protect the load of the converter (e.g. a large windmill generator) against asymmetric short-circuit currents and alternating torques, see Chapter 5. For this purpose, the surge-current mode of the IGBT is introduced and verified. It will be shown that this special mode can be handled by the IGBT without destruction or significant ageing. To meet the requirements and test conditions mentioned above, a singlechip test bench was constructed. New phenomena like the self-turn-off mechanism or special IGBT destructions under short-circuit and surge-current mode were studied in detail. Countermeasures were found to protect the IGBT and the complete power-electronic circuit and application from a possible destruction. 

domingo, 23 de maio de 2021

ИССЛЕДОВАНИЕ И РАЗРАБОТКА ЭНЕРГОПРЕОБРАЗУЮЩЕЙ АППАРАТУРЫ ВЫСОКОВОЛЬТНЫХ СИСТЕМ ЭЛЕКТРОПИТАНИЯ КОСМИЧЕСКИХ АППАРАТОВ-Черная Мария Михайловна-RESEARCH AND DEVELOPMENT OF POWER CONVERSION EQUIPMENT FOR HIGH VOLTAGE POWER SUPPLY SYSTEMS FOR SPACE VEHICLES BY --Maria Mikhailovna-






 Федеральное государственное бюджетное образовательное учреждение высшего образования «ТОМСКИЙ ГОСУДАРСТВЕННЫЙ УНИВЕРСИТЕТ СИСТЕМ УПРАВЛЕНИЯ И РАДИОЭЛЕКТРОНИКИ» (ТУСУР) 

Черная Мария Михайловна 

ИССЛЕДОВАНИЕ И РАЗРАБОТКА ЭНЕРГОПРЕОБРАЗУЮЩЕЙ АППАРАТУРЫ ВЫСОКОВОЛЬТНЫХ СИСТЕМ ЭЛЕКТРОПИТАНИЯ КОСМИЧЕСКИХ АППАРАТОВ 

05.09.12 – Силовая электроника

 Dissertation for an academic degree candidate of technical sciences Scientific adviser: Doctor of Technical Sciences, Yu.A. Shinyakov


INTRODUCTION Relevance of the topic. 
Power supply system (EPS) of the automatic spacecraft (SC) is a set of energy sources and energy-converting equipment (EPA), which stabilizes the voltage of the output power line of the load and distribution of energy flows in the PDS in accordance with the operating modes of the system and operating conditions of the spacecraft.
Significant contribution to the creation of scientific and technical groundwork in the development and the creation of power supply systems for automatic spacecraft was made by the teams of the leading enterprises of the Russian Space Agency: JSC "Information Satellite systems "them. acad. M.F. Reshetnev (Zheleznogorsk), FSUE NPO im. S.A. Lavochkin "(g. Khrunichev State Research and Production Center (Moscow), RSC Energia im. S.P. Korolev (Korolev) and others. They solve the problems of overcoming technological barriers and solving urgent scientific and technological problems, on development and implementation of innovations, ground testing of BOT, flight tests and support during the normal operation of the spacecraft.

Inversores integrados monofásicos e trifásicos para aplicações fotovoltaicas: técnicas para obtenção de mppt, detecção e proteção de ilhamento, sincronização e paralelismo com a rede de distribuição de energia elétrica-Moacyr Aureliano Gomes de Brito--Faculdade de Engenharia de Ilha Solteira-


Moacyr Aureliano Gomes de Brito

 Inversores Integrados Monofásicos e Trifásicos para Aplicações Fotovoltaicas: Técnicas para obtenção de MPPT, detecção e proteção de ilhamento, sincronização e paralelismo com a rede de distribuição de energia elétrica 

Tese submetida à Faculdade de Engenharia de Ilha Solteira – FEIS/UNESP – como parte dos requisitos exigidos para a obtenção do título de Doutor em Engenharia Elétrica. Orientador Prof. Dr. Carlos Alberto Canesin Ilha Solteira. 2013.

Resumo
 Esta proposta de tese se baseia na necessidade atual e tendência mundial na busca por sistemas cada vez mais eficientes e que se baseiem em fontes de energia alternativas menos poluentes, renováveis e que produzam pouco impacto ambiental. Desta forma, são desenvolvidos sistemas de geração de energia elétrica de pequeno porte baseado em painéis solares fotovoltaicos. Com o intuito de aumentar o rendimento e a densidade de potência dos sistemas, são apresentadas novas estruturas de inversores monofásicos e trifásicos integrados para aplicação como sistemas isolados e/ou conectados à rede de distribuição em corrente alternada (CA), operando como sistemas de geração distribuídos. Os inversores integrados são apresentados com o intuito de substituir os usuais sistemas de conversão de energia a duplo estágio. Incorporado aos inversores integrados são implementados métodos e dispositivos para extração da máxima potência possível dos painéis fotovoltaicos (algoritmo de MPPT), aumentando assim o aproveitamento de energia advinda destes painéis. Além disso, em virtude da necessidade de conexão segura destes sistemas à rede de distribuição de energia elétrica em corrente alternada, são realizadas análises e a implementação de métodos de sincronismo com a rede de CA em baixa tensão; além da análise e síntese de métodos híbridos para detecção e gestão do efeito de ilhamento, a fim de garantir a segurança do sistema. O controle dos conversores e as técnicas de MPPT, gestão e detecção de ilhamento, bem como de sincronismo com a rede em CA são implementadas de forma digital, com o objetivo de propiciar maior flexibilidade na concepção das lógicas de controle adequadas às aplicações propostas. Finalmente, destaca-se que o trabalho trouxe contribuições significativas para a melhoria na implementação dos algoritmos de MPPT P&O e IC, que foram denominados de P&O e IC baseados em PI. Também foram apresentadas as etapas de integração para a obtenção de novas famílias de inversores integrados monofásicos e trifásicos, destacando a inovação das topologias ZETA/Cuk integradas. Ainda, destaca-se que esta é a primeira tese que apresenta os inversores tri-state trifásicos em conexão com a rede de distribuição de energia elétrica. Inversores estes que foram dotados de uma inovação no controle e em sua modulação, que leva ao controle independente entre entrada e saída, facilitando a busca do MPPT e a injeção de potência na rede elétrica. Palavras-Chave: Conversão fotovoltaica. Inversores integrados. MPPT. Ilhamento e sincronismo.

quinta-feira, 20 de maio de 2021

High Frequency GaN Characterization and Design Considerations by Xiucheng Huang-Virginia Polytechnic Institute and State University


 High Frequency GaN Characterization and Design Considerations by Xiucheng Huang Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy In Electrical Engineering 

 Fred C. Lee, Chair Qiang Li Dong S. Ha Jaime De La Ree Alfred L. Wicks
 Sep 6th, 2016 Blacksburg, Virginia

 High Frequency GaN Characterization and Design Considerations Xiucheng Huang 

ABSTRACT
The future power conversion system not only must meet the characteristics demanded by the load, but also have to achieve high power density with high efficiency, high ambient temperature, and high reliability. Density and efficiency are two key drivers and metrics for the advancement of power conversion technologies. Generally speaking, a high performance active device is the first force to push power density to meet the requirement of modern systems. Silicon has been a dominant material in power management since the late 1950s. However, due to continuous device optimizations and improvements in the production process, the material properties of silicon have increasingly become the limiting factor. Workarounds like the super junction stretch the limits but usually at substantial cost. The use of gallium nitride devices is gathering momentum, with a number of recent market introductions for a wide range of applications such as point-of-load (POL) converters, off-line switching power supplies, battery chargers and motor drives. GaN devices have a much lower gate charge and lower output capacitance than silicon MOSFETs and, therefore, are capable of operating at a switching frequency 10 times greater. This can significantly impact the power density of power converters, their form factor, and even current design and manufacturing practices. To realize the benefits of GaN devices resulting from significantly higher operating frequencies, a number of issues have to be addressed, such as converter topology, soft-switching technique, high frequency gate driver, high frequency magnetics, packaging, control, and thermal management. This work studies the insight switching characteristics of high-voltage GaN devices including some specific issues related to the cascode GaN. The package impact on the switching performance and device reliability will be illustrated in details. A stack-die package is proposed for cascode GaN devices to minimize the impact of package parasitic inductance on switching transition. Comparison of hard-switching and soft-switching operation is carried based on device model and experiments, which shows the necessity of soft-switching for GaN devices at high frequency. This work also addresses high dv/dt and di/dt related gate drive issues associated with the higher switching speed of GaN devices. Particularly, the conventional driving solution could fail on the high side switch in a half-bridge configuration due to relative large common-mode noise current. Two simple and effective driving methods are proposed to improve noise immunity and maintain high driving speed.

terça-feira, 18 de maio de 2021

A Digital Control System for UPS Systems with Smart Grid Capability Mardani Boroujeni, Fatemeh-UNIVERSIY DE CALGARY-DEGREE OF MASTER OF SCIENCE GRADUATE PROGRAM IN ELECTRICAL ENGINEERING


A Digital Control System for UPS Systems with Smart Grid Capability Mardani Boroujeni, Fatemeh THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL
 FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE GRADUATE PROGRAM IN ELECTRICAL ENGINEERING
UNIVERSITY CALGARY, ALBERTA AUGUST, 2019.
 Abstract 
Smart grids have recently become the center of attention for modernizing the grid system. In future smart-grids, energy storage systems are one of the key components, which can complement intermittent renewable energy sources and in turn increase reliability and eciency of the grid system. Modern Uninterruptible Power Supply (UPS) systems can provide storage capacity for future smart grids since they usually include batteries. UPS systems can also provide instant electrical power to sensitive equipment and grid during various events such as brownout, power failures, spikes, voltage surges, EMI/RF noise, and frequency variations. Future UPS systems require to have much better dynamics in order to deal with transients. The control system of UPS systems mainly determines their dynamical performance and transient response. The existing state-of-the-art UPS control systems are based on linear PI controllers for the most part. Thus, current UPS systems usually show a sluggish transient response and they are not suited for future smart grid applications where instant power is required to maintain the system. In this thesis, new UPS systems with improved transient response are proposed. The proposed UPS system utilities a new controller that is able to improve the dynamic performance and allows for various smart grid functionalities. The proposed control system is based on the adaptive control theory, which adaptively changes the controller's parameters based on the UPS operating conditions. Furthermore, the proposed control system isolates the double-frequency ripple from the battery in the normal/charging mode as well as in the backup/discharging mode. Therefore, the new UPS system is well-suited for single-phase systems utilizing lithium-ion battery as storage. Mathematical analysis, simulation, and experimental results are presented to verify the performance of the proposed control system and demonstrate its superior performance.