Orientador: Carlos Alberto Canesin / Resumo: Uma das principais dificuldades para a adoção dos veículos elétricos (VE) é o tempo de abastecimento (carregamento elétrico), considerado elevado quando comparado com o tempo requerido para abastecer um veículo com motor a combustão interna. O carregamento do VE típico de passageiros é geralmente realizado na residência do proprietário, ligando o carregador interno do VE em uma tomada convencional monofásica. Este método de carregamento é conhecido como de Corrente Alternada (CA), requer, tipicamente pelo menos 7 horas para fornecer uma carga completa. Por outro lado, o método de carregamento por Corrente Continua (CC) oferece tempos de carregamento entre 10 e 80 minutos. Contudo, para obter este nível de desempenho, são empregados carregadores externos de alta potência ligados de forma direta ao banco de baterias do VE. Devido ao custo e aos requerimentos de alimentação, estes carregadores rápidos são usados principalmente em aplicações públicas e comerciais. As pesquisas pelas melhores topologias a serem empregadas nos carregadores rápidos ainda são, neste ano de 2017 objeto de estudos em escala mundial. Neste contexto, este trabalho descreve a análise e implementação de um protótipo de carregador externo rápido para VE, o qual é composto por um retificador híbrido trifásico com correção ativa do fator de potência (Etapa CA-CC), seguido de um conversor tipo Buck entrelaçado (Etapa CC-CC). Na etapa CA-CC são impostas correntes de entrada senoidais, obtendo desta forma uma r... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Submitted by CAMILO ALEXEY SUAREZ BUITRAGO null (camiloalexey@gmail.com) on 2017-05-05T23:51:03Z No. of bitstreams: 1 CAMILO ALEXEY SUAREZ BUITRAGO.pdf: 4865572 bytes, checksum: e8593c9e425def26a441b4b919b9d371 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-05-08T16:36:05Z (GMT) No. of bitstreams: 1 suarezbuitrago_ca_me_ilha.pdf: 4865572 bytes, checksum: e8593c9e425def26a441b4b919b9d371 (MD5) / Made available in DSpace on 2017-05-08T16:36:05Z (GMT). No. of bitstreams: 1 suarezbuitrago_ca_me_ilha.pdf: 4865572 bytes, checksum: e8593c9e425def26a441b4b919b9d371 (MD5) Previous issue date: 2017-03-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Uma das principais dificuldades para a adoção dos veículos elétricos (VE) é o tempo de abastecimento (carregamento elétrico), considerado elevado quando comparado com o tempo requerido para abastecer um veículo com motor a combustão interna. O carregamento do VE típico de passageiros é geralmente realizado na residência do proprietário, ligando o carregador interno do VE em uma tomada convencional monofásica. Este método de carregamento é conhecido como de Corrente Alternada (CA), requer, tipicamente pelo menos 7 horas para fornecer uma carga completa. Por outro lado, o método de carregamento por Corrente Continua (CC) oferece tempos de carregamento entre 10 e 80 minutos. Contudo, para obter este nível de desempenho, são empregados carregadores externos de alta potência ligados de forma direta ao banco de baterias do VE. Devido ao custo e aos requerimentos de alimentação, estes carregadores rápidos são usados principalmente em aplicações públicas e comerciais. As pesquisas pelas melhores topologias a serem empregadas nos carregadores rápidos ainda são, neste ano de 2017 objeto de estudos em escala mundial. Neste contexto, este trabalho descreve a análise e implementação de um protótipo de carregador externo rápido para VE, o qual é composto por um retificador híbrido trifásico com correção ativa do fator de potência (Etapa CA-CC), seguido de um conversor tipo Buck entrelaçado (Etapa CC-CC). Na etapa CA-CC são impostas correntes de entrada senoidais, obtendo desta forma uma reduzida distorção harmônica total (DHT). Nesta etapa são empregados retificadores SEPIC comutados sob corrente nula (Zero Current Switching, ZCS) controlados por uma simples modulação por histerese, em paralelo com um retificador trifásico a diodos de seis pulsos. O estágio SEPIC processa apenas uma fração da potência total entregue pelo retificador híbrido, reduzindo deste modo os esforços de corrente dos semicondutores empregados, permitindo o uso desta topologia em elevados níveis de potência. Na etapa CC-CC o conversor Buck entrelaçado é controlado por modulação de largura de pulso (Pulse-Width Modulation, PWM), permitindo assim a implantação da técnica de carregamento por corrente constante e tensão constante (Constant Current-Constant Voltage, CC-CV), comumente empregada em baterias de íons de lítio e supercapacitores (SC). Como principal resultado foi obtido o carregamento de um banco de supercapacitores de 2,54 F, com corrente constante de 20 A, variando sua tensão de 180 V a 270 V com uma duração de 40 s, obtendo uma distorção harmônica total de 3,52% na corrente de entrada, ajustando-se ao padrão IEEE 2030.1.1-2015. / One of the main barriers against electric vehicle (EV) adoption is related to the battery recharging time, which is relatively high when compared to the time required to fill up a gasoline/diesel internal combustion engine vehicle. EV charging generally is done at home, using the on-board EV charger tied to conventional single phase power inlet, this charging method is known as Alternating Current (AC) and takes at least 7 hours to provide a full charge. On the other hand, the Direct Current (DC) method offers charging times from 1.2 hours to 10 minutes. However, to reach this performance, high power off-board chargers also known as fast-chargers (FC), directly charge the EV battery bank. Due to its cost and power supply requirements FC are used only in public or commercial applications. The researches for the best FC topologies are an active area of studies over the world. This work describes the analysis and implementation of an off-board electric vehicle (EV) Fast Charger prototype. It is composed by a three-phase hybrid rectifier with power factor correction (AC/DC stage), followed by an interleaved buck converter (DC/DC stage). At AC/DC stage, sinusoidal input phase currents are imposed, and consequently low Total Harmonic Distortion (THD) is obtained by the use of Zero Current Switching (ZCS) SEPIC rectifiers, applying a simple hysteresis control technique, in parallel with a conventional three-phase six pulses diode rectifier. The SEPIC converters manage only a fraction of the total power delivered by the hybrid rectifier, reducing the semiconductors current stresses, and allowing the use of this topology for high power levels. At DC/DC stage, the interleaved buck converter is controlled by Pulse Width Modulation (PWM), allowing Constant Current–Constant Voltage (CC-CV) charging technique, typically used for Lithium-ion (Li) batteries and Supercapacitors (SC). As main result of this implementation was obtained a charging process using constant a constant current of 20A over a supercapacitor bank of 2,54 F, raising its voltage from 180V to 270V in less than 40s, having a input phase current THD of 3,52%, fulfilling the requirements of IEEE 2030.1.1-2015 standard.

Wave energy converter (WEC) harnesses energy from the ocean to produce electrical power. The electrical power produced by the WEC is fluctuating and is not maximized as well, due to the varying ocean conditions. As a consequence, without any intermediate power conversion stage, the output power from the WEC can not be fed into the grid. To feed WEC output power into the grid, a two-stage power conversion topology is used, where the WEC output power is first converted into DCpower through rectification, and then a DC-AC converter (inverter) is used to supply AC power into the grid. The main motive of this research is to extract maximum electrical power from the WEC by active rectification and smoothing the power fluctuation of the wave energy converter through a hybrid energy storage system consisting of battery and flywheel. This research also illustrates active and reactive power injection to the grid according to load demand through a voltage source inverter.

The objective of this master's thesis is new power converter design for bicycle with combustion engine and electric power transmission. The power converter is control by microprocessor and control algorithm is designed to achieve maximum efficiently of combustion engine. Converter and servomotor for controlling combustion engine throttle are located in metal box. Hardware, firmware and metal box are designed in the thesis.

Object my master’s thesis is the design a Medical device uninterruptible power supply with managment system utilizing I2C bus. Norm EN 61000-3-2 define electric parameters for medical device power supply. In case of power supply for medial equipment is expressive accent on increased electric strength. This power supply have usually primary and secondary power circuit. Primary power circuit form line accumulator, which supplies needed output to the load and recharge reserve battery. Secondary is formed battery-pack, which serve as back-up power supply at drop-out prime circle. They have a minimum weight, small proportions, large overall effectivity also charging battery-pack and monitoring battery-pack charging condition. Result whole those master’s thesis is design Medical device uninterruptible power supply with managment system utilizing I2C bus and realization board layout. Resulting characteristics designed supply unit are: Output voltages are 5V/ 3 A , 12V/ 1,5 A and -12V/ 0,1 A. Managment support information about: Line adapter/ battery pack switch, battery-pack charging condition and actuall tempera-ture battery-pack.

The master‘s thesis deals with DC/DC converters for power LED diodes. Gives an overview of the field of LED lighting technology, analyzes various types of converters and shows their principle of operation. Furthermore presents some possible circuit designs for three different voltage levels and the calculations for each part. As an approval of their functionality the results of their measurements are plotted followed by the data evaluation.

This work deals with high power pulse converters (tens of kW) using new semiconductor devices of silicon carbide (SiC). Firstly the current state of the issue is analyzed. A research in a specific area of high power buck converters with pulse transformer follows. There was a strong emphasis on minimizing size and weight. The design process was focused also on reliability and robustness. To achieve the defined objectives, it was necessary to use the latest available switching transistors and diodes, and an unusually high switching frequency (100 kHz at a power of about 16 kW). Due to the high switching frequency, we achieved small size of pulse transformers and output chokes. An optimization of high-frequency pulse transformer with demand on minimum volume and weight of core and windings represents a separate theoretical part of the thesis. There have been proposed several analytical solutions of optimization problems, the results of which could overlap with the implementation in practice of switching power supplies. The combination of high switching frequency, fast semiconductors and the high power brings various parasitic effects to the power circuit. In the thesis, these parasitic effects are analyzed. Solutions which minimize or completely remove those effects were theoretically designed and successfully implemented, tested and finalized in experimental part of the work. Detailed description of the implementation of functional sample and series of validation measurements are included in the final part.

No description available.

KTH is funding a project whose goal is to send a satellite into space. This project is called MIST (Miniature Student Satellite) which is assembled by a team of students at KTH. On the satellite there are experiments that are invented by other teams, in two of those experiments a power supply is required. This thesis is a technical investigation on how to design the power supply to both of those experiments, which are called SiC and Piezo LEGS. Piezo LEGS will investigate how their nanosized motors will behave and function in a space environment. SiC will investigate how their silicone carbide transistors will be affected by the space environment. A team made of four other students was selected to produce SiC experiments and a PCB in which this work is included. A literature study was done to get a better understanding of how power supplies work and to know how to select a good power supply. When the power supplies were selected they were simulated to meet the requirements. The next step was to do a Printed Circuit Board(PCB) for the SiC experiment and Piezo LEGS to be able to test the power supplies functionality in the physical world. Both of the converters reached the required output and characteristics working on their respective PCB. More time is needed for long time testing and optimization on the PCB layouts. / MIST (Miniature Student Satellite) är ett av KTH subventionerat projekt vilket har som mål att skicka upp en satellit i rymden. Projektet kommer omfatta flera olika experiment. Piezo LEGS ska undersöka en motors funktionalitet i rymdmiljö. SiC ska undersöka hur Silicon carbide halvledare och transistorer påverkas av rymdmiljön. Båda experimenten kräver varsin strömförsörjning för att fungera. Detta projekt ska undersöka kraven på strömförsörjning samt testa prototypen av ett kretskort för densamma. Först genomfördes en förstudie av de två typer av regulatorer som vanligtvis används som strömförsörjning, den linjära regulatorn och switch-mode regulatorn för att förklara olika strömförsörjningsteknologier, samt ta reda på de olika miljökraven. Baserat på förstudiens resultat erhölls kunskap för hur tester ska tas fram för funktionalitet av regulatorerna så att de når kraven för MIST för att sedan kunna producera de båda regulatorerna. Målet är att resultatet av simuleringarna på strömförsörjningen ska stämma överens med utfallet av kretskorten som produceras. Mätningar genomfördes på prototyp kretskort som visade att simuleringarna var korrekta och gav strömförsörjningen rätt resultat på kretskorten. Några av funktionerna på regulatorerna hann ej testas på grund av tidsbrist och mycket framtida arbete kvarstår.

Digitally controlled switching DC-DC converters have recently emerged as an attractive alternative to conventional switching converters based on analog control techniques. This research focuses on eliminating the issues associated with the state of the art switching converters by proposing three novel control techniques: (1) a digitally controlled Buck-Boost converter uses a fully synthesized constant ON/OFF time-based fractional-N controller to regulate the output over a 3.3V-to-5.5V input voltage range and provides seamless transition from buck to buck-boost modes (2) a hysteretic buck converter that employs a highly digital hybrid voltage/current mode control to regulate output voltage and switching frequency independently (3) a 10MHz continuous time PID controller using time based signal processing which alleviates the speed limitations associated with conventional analog and digital. All the three techniques employ digitally assisted control techniques and require no external compensation thus making the controllers fully integrated and highly cost effective. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from June 25, 2012 - June 25, 2014