Desenvolvimento de UPS trifásica de alto rendimento utilizando MOSFETS de carbeto de silício Autor Wendell da Cunha Alves. - 2018-Dissertação (mestrado) Universidade Federal de Minas Gerais, Escola de Engenharia.

 

DESENVOLVIMENTO DE UPS TRIFASICA DE ALTO RENDIMENTO UTILIZANDO MOSFETS DE CARBETO DE SILICIO 

AUTOR WENDELL DA CUNHA ALVES 

PROGRAMA DE PÓS-GRADUAÇÃO EM ENGENHARIA ELETRICA UNIVERSIDADE FEDERAL DE MINAS GERAIS- BRASIL

 Resumo

 Com o constante aumento do consumo de energia no mundo, a eficiência dos sistemas e equipamentos está se tornando cada vez mais importante. A UPS é um equipamento que fornece alimentação segura e confiável para sistemas de carga crítica, ou seja, sistemas em que uma interrupção do fornecimento pode levar a perdas econômicas ou até mesmo humanas. A UPS de dupla conversão é a classe UPS mais completa em termos de proteção da carga, regulação, desempenho e confiabilidade, no entanto, tem menor rendimento e maior custo por causa de seu elevado número de conversores eletrônicos de energia. Os dispositivos de Carbeto de Silício estão emergindo como uma oportunidade para construir conversores eletrônicos com maior eficiência e maior densidade de potência. O objetivo principal deste trabalho é projetar um conversor trifásico c.a.-c.c.-c.a. usando Carbeto de Silício para aplicações de UPS de dupla conversão. Para maximizar a eficiência e minimizar o custo, uma comparação é feita para guiar a seleção das topologias de conversor utilizadas. A comparação é feita sob duas condições de operação. Ao final da comparação, dois conversores c.a.-c.c.-c.a. com boa relação custo-benefício são propostos, um para cada condição. Em seguida, um dos conversores propostos é projetado, simulado e construído. As metodologias para dimensionar e escolher os principais componentes de hardware são descritas em detalhes. A operação do conversor e sua técnica de controle são validadas por meio de simulações no software PSIM. Os resultados experimentais obtidos com o protótipo comprovam o alto rendimento alcançável com MOSFETs de Carbeto de Silício. 

Palavras-chave: UPS. Carbeto de Silício. Conversores eletrônicos. Projeto. Alto rendimento.

LINK: https://www.ppgee.ufmg.br/defesas/1583M.PDF

XXIII Congresso Brasileiro de Automática (CBA 2020) 23 e 26 de Novembro de 2020- CONGRESSO VIRTUAL

 

O XXIII Congresso Brasileiro de Automática (CBA 2020) acontecerá entre os dias 23 e 26 de Novembro de 2020, na modalidade de evento virtual.

 A organização é realizada em parceria pela Universidade Federal de Santa Maria (UFSM), Pontifícia Universidade Católica (PUCRS) e a Universidade do Vale do Rio dos Sinos (UNISINOS), vinculado à Sociedade Brasileira de Automática (SBA). O CBA é realizado bianualmente e, desde 1976, é o maior congresso na área de Engenharia Elétrica do Brasil. O congresso conta com a participação expressiva de pesquisadores e profissionais atuantes em diversas áreas da engenharia elétrica, vindos das várias regiões do Brasil e de outros países, promovendo a integração das comunidades científicas, acadêmicas e industriais. O evento tem como base os temas aplicados às áreas que circundam os ramos da engenharia elétrica, com destaque para automação e controle, eletrônica de potência, instrumentação, robótica, sistemas de potência, fontes alternativas de energia, armazenamento de energia, redes elétricas inteligentes, microrredes, mobilidade elétrica e outras áreas afins ao tema central. A edição de 2020 contará com minicursos, sessões plenárias, sessões técnicas, entre outros, com participação de palestrantes renomados e o que há de mais inovador no mundo da engenharia.

LINK PAGINA WEB ORIGINAL: https://cba2020.galoa.com.br/

Multi-powered UPS --Department of Electrical Engineering Graduate School, Chonnam National University Author KIM Jongcheo -Master's Thesis

 Multi-powered UPS KIM Jong Cheol Department of Electrical Engineering Graduate School, Chonnam National University (Supervised by Professor PARK Sungjun)

(Abstract)  As the society develops, load sensitive to power environment such as medical equipment, communication equipment, FA (factory automation) system and data center server is widely used, and reliability and stable supply of power system becomes more important. In particular, electrical equipment used for military purposes is not expected to have any problems in the power supply system during exhibition or operation, so it is becoming necessary to secure a reserve energy source, to duplicate the system or to make surplus system. Even if the reliability of the power supply system is high, momentary power failure due to an accident or a lightning can not be avoided, and there is also a momentary voltage drop (Sag) or a voltage rise (swell) of the power supply. Table 1 below is a definition of the power anomaly phenomenon that appears in the commercial power source shown in IEEE Std 1159TM-2009.

In case of power-sensitive load, it is necessary to prepare for system failure because it can cause fatal damage even in short-term system failure. Therefore, there is a need for an uninterruptible power supply (UPS) [1] [2] to compensate for instantaneous voltage fluctuations as well as for blackout situations.

Automotive UPS systems typically consist of a single module, such as a battery, bi-directional inverter, high-speed switch, and the UPS module is connected to the vehicle generator and critical loads. If the existing UPS system is composed of a single power source and the UPS system is composed of only one power source, it is difficult to cope with the demand of the main load in the long term only by the output of the UPS when the power source is out of power. To solve this problem, connecting several power sources to a load leads to a large increase in cost due to the connection of UPS to each power source. It is an off-line UPS system that is commonly used. The advantage of the off-line method is that when the input power is normal, there is less generation of electromagnetic waves and noise, and the power consumption is low due to high energy efficiency. In addition, it has a simple circuit configuration, high durability, low cost, and miniaturization compared to on-line. The disadvantage of off-line is that momentary power cut-off occurs in the case of power failure, and the output changes according to the input voltage change during non-operation, making it difficult to adjust the voltage and therefore it is not suitable for high-precision load. In the case of Figure 1, it is composed of a single power source, and if the UPS system consists of only one power source, it is difficult to cope with the demand of the main load in the long term only by the output of the UPS when the power source is outage. In particular, in a system having a purpose for use in a command communication terminal of a military, it is difficult to supply stable power because there are many variables in power supply.

In this paper, we propose a multi - power applied UPS system that eliminates the disadvantages of the parallel - connected power supply and has a fast switching time. The UPS system operates in the battery charging mode when the system is in normal operation and operates in the UPS mode, which is the battery discharge mode, in the event of a system failure. In such a mode switching, the follow up of the command voltage should be performed within the shortest time. Since the UPS must supply the same voltage to the load within 4ms in case of a system fault, the switching time and return time must be short when controlling the output voltage and current of the UPS, and the power failure detection time is also important. In addition, since the main loads of the UPS system are mostly time-varying and non-linear loads, it is also necessary to be able to control non-linear loads. Conventionally, a proportional integral (PI) controller has been used as a control method of such a UPS system. The PI controller has a very stable output characteristic in the steady state, but it takes a long time to reach the steady state at the time of mode change or load change due to slow acceleration. Therefore, due to the limit of the transient response characteristic of the controller, it is difficult to perform stable power supply within a short time in the case of a system fault. Also, since the gain of the PI controller affects the response characteristics, response characteristics may be slow or overshoot may occur depending on the gain value selection of the controller. Therefore, in this paper, to compensate the limitation of the proportional integral controller, the controller using the DFT with fast electrostatic sensing characteristics is applied. The control using DFT has an advantage that it can perform fast power failure detection by comparing grid voltage waveform and voltage waveform created by DFT using Schmitt trigger. Therefore, stable power supply is possible when using only PI control in mode switching in UPS system. The multi-power applied UPS system proposed in this paper is finally designed to satisfy the following conditions. In case of system fault, detection method using fast DFT is applied to the electrostatic detection in order to supply stable power to the load in a shorter time than the conventional PI control method. At this time, the switching time of mode switching was set to be less than 4 ms, which is 1/4 of the system cycle, according to KS C 4310 regulation of the uninterruptible power supply in the industry standard council. A 10kW UPS system, in which commercial voltage, vehicle generator, and auxiliary diesel generator can be connected to the proposed switchgear, was tested and validated.

LINK1:http://www.riss.kr/search/detail/DetailView.do?p_mat_type=be54d9b8bc7cdb09&control_no=8f6a0e4c451565dbffe0bdc3ef48d419

LINK2:http://www.mediafire.com/file/0bg7thkijs1736t/MULTIPOWERED+UPS.pdf/file

High Frequency (MHz) Planar Transformers for Next Generation Switch Mode Power Supplies by Radhika Ambatipudi -Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.(Power Electronics)

 High Frequency (MHz) Planar Transformers for Next Generation Switch Mode Power Supplies

by Ambatipudi, Radhika

Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.(Power Electronics) 2013 (English) Doctoral thesis

 ABSTRACT

 Increasing the power density of power electronic converters while reducing or maintaining the same cost, offers a higher potential to meet the current trend in relation to various power electronic applications. High power density converters can be achieved by increasing the switching frequency, due to which the bulkiest parts, such as transformer, inductors and the capacitor's size in the converter circuit can be drastically reduced. In this regard, highly integrated planar magnetics are considered as an effective approach compared to the conventional wire wound transformers in modern switch mode power supplies (SMPS). However, as the operating frequency of the transformers increase from several hundred kHz to MHz, numerous problems arise such as skin and proximity effects due to the induced eddy currents in the windings, leakage inductance and unbalanced magnetic flux distribution. In addition to this, the core losses which are functional dependent on frequency gets elevated as the operating frequency increases. Therefore, this thesis provides an insight towards the problems related to the high frequency magnetics and proposes a solution with regards to different aspects in relation to designing high power density, energy efficient transformers.

The first part of the thesis concentrates on the investigation of high power density and highly energy efficient coreless printed circuit board (PCB) step-down transformers useful for stringent height DC-DC converter applications, where the core losses are being completely eliminated. These transformers also maintain the advantages offered by existing core based transformers such as, high coupling coefficient, sufficient input impedance, high energy efficiency and wide frequency bandwidth with the assistance of a resonant technique. In this regard, several coreless PCB step down transformers of different turn’s ratio for power transfer applications have been designed and evaluated. The designed multilayered coreless PCB transformers for telecom and PoE applications of 8, 15 and 30W show that the volume reduction of approximately 40 - 90% is possible when compared to its existing core based counterparts while maintaining the energy efficiency of the transformers in the range of 90 - 97%. The estimation of EMI emissions from the designed transformers for the given power transfer application proves that the amount of radiated EMI from a multilayered transformer is less than that of the two layered transformer because of the decreased radius for the same amount of inductance.

The design guidelines for the multilayered coreless PCB step-down transformer for the given power transfer application has been proposed. The designed transformer of 10mm radius has been characterized up to the power level of 50W and possesses a record power density of 107W/cm3 with a peak energy efficiency of 96%. In addition to this, the design guidelines of the signal transformer for driving the high side MOSFET in double ended converter topologies have been proposed. The measured power consumption of the high side gate drive circuit together with the designed signal transformer is 0.37W. Both these signal and power transformers have been successfully implemented in a resonant converter topology in the switching frequency range of 2.4 – 2.75MHz for the maximum load power of 34.5W resulting in the peak energy efficiency of converter as 86.5%.

This thesis also investigates the indirect effect of the dielectric laminate on the magnetic field intensity and current density distribution in the planar power transformers with the assistance of finite element analysis (FEA). The significance of the high frequency dielectric laminate compared to FR-4 laminate in terms of energy efficiency of planar power transformers in MHz frequency region is also explored.

The investigations were also conducted on different winding strategies such as conventional solid winding and the parallel winding strategies, which play an important role in the design and development of a high frequency transformer and suggested a better choice in the case of transformers operating in the MHz frequency region.

In the second part of the thesis, a novel planar power transformer with hybrid core structure has been designed and evaluated in the MHz frequency region. The design guidelines of the energy efficient high frequency planar power transformer for the given power transfer application have been proposed. The designed core based planar transformer has been characterized up to the power level of 50W and possess a power density of 47W/cm3 with maximum energy efficiency of 97%. This transformer has been evaluated successfully in the resonant converter topology within the switching frequency range of 3 – 4.5MHz. The peak energy efficiency of the converter is reported to be 92% and the converter has been tested for the maximum power level of 45W, which is suitable for consumer applications such as laptop adapters. In addition to this, a record power density transformer has been designed with a custom made pot core and has been characterized in the frequency range of 1 - 10MHz. The power density of this custom core transformer operating at 6.78MHz frequency is 67W/cm3 and with the peak energy efficiency of 98%.

LINK ORIGINAL NA WEB:

https://www.diva-portal.org/smash/get/diva2:665725/FULLTEXT01.pdf

Étude et élaboration d’un système de surveillance et de maintenance prédictive pour les condensateurs et les batteries utilisés dans les Alimentations Sans Interruptions (ASI) by Mohamed Karim Abdennadher - Study and elaboration of a monitoring and predictive maintenance system for capacitors and batteries used in Uninterruptible Power Supplies (UPS)

 

Étude et élaboration d’un système de surveillance et de maintenance prédictive pour les condensateurs et les batteries utilisés dans les Alimentations Sans Interruptions (ASI) Mohamed Karim Abdennadher

Study and elaboration of a monitoring and predictive maintenance system for capacitors and batteries used in Uninterruptible Power Supplies (UPS)

THESE DE DOCTORAT Présentée devant L’UNIVERSITE CLAUDE BERNARD LYON 1 Pour l’obtention du grade de DOCTEUR de l’UNIVERSITE de LYON 1 (Arrêté du 07 Août 2006) Spécialité : GENIE ELECTRIQUE Préparée au sein de L’ECOLE DOCTORALE ELECTRONIQUE, ELECTROTECHNIQUE, AUTOMATIQUE DE LYON Par M. Mohamed Karim ABDENNADHER

Résumé

 To ensure power quality and permanently, some electronic system supplies exist. These supplies are the Uninterrupted Power Supplies (UPS). An UPS like any other system may have some failures. This can be a cause of redundancy loss. This load loss causes a maintenance downtime which may represent a high cost. We propose in this thesis to work on two of the most sensitive components in the UPS namely electrolytic capacitors and lead acid batteries. In a first phase, we present the existing surveillance systems for these two components, highlighting their main drawbacks. This allows us to propose the specifications which have to be implemented for this system. For electrolytic capacitors, we detail different stages of characterization ; the aging accelerated standard experimental procedure and their associated results. On the other hand, we present the simulation results of monitoring and failure prediction system retained. We discuss the experimental validation, describing the developed system. We detail the electronic boards designed, implemented algorithms and their respective constraints for a real time implementation. Finally, for lead acid batteries, we present the simulation results of the monitoring system adopted to obtain the SOC and SOH. We describe the aging experimental procedure of charging and discharging cycles of the batteries needed to find a simple and accurate electric models. We explain the aging experimental results and in the end we give suggestions for improving our system to get a more accurate SOH.

LINK:  https://tel.archives-ouvertes.fr/tel-00532642v2/document