本研究主要探討電源供應器產業之突破式創新的可能性。透過文獻了解創新的涵意和學者對創新的分類，深入比較「維持性創新」（Sustaining Innovation）與其高階入侵（High-end encroachment），以及「突破式創新」（Disruptive Innovation）之三種低階入侵（Low-end encroachment）方式，分別為：即刻市場入侵（Immediate low-end encroachment）、邊緣市場入侵（Fringe-market low-end encroachment）、分離市場入侵（ Detached-market low-end encroachment）。 首先探究電源供應器之技術、產業現況、供應鏈結構及電源供應器的應用分類；將無線充電器歸類為新科技，針對無線充電技術的市場、聯盟、應用、未來機會做深入的剖析。為驗證無線充電技術之突破式創新的可能性分析，本研究採取學者Schmidt（2008）所提之「辨別創新的三步驟」進行突破性創新的驗證，以「無線方便性」與「充電速度」為關鍵指標。現有充電器的消費者比較重視「充電速度」，而新市場的消費者比較在意「無線方便性」，兩者的需求曲線不同，無線充電科技因提供與既有市場不同的新功能，所以被歸類為「低端突破式創新」之「分離市場」入侵。分離市場的消費者願意為無線的方便性付出較高的價格購買新產品。在新產品推出初期不會侵蝕主流市場的銷售，但經過一段時間，當價格下降及充電速度性能提升後，新產品會「低端突破」原有市場；到最後，新產品會往主流市場及高階市場擴散而影響既有產業和原來的市場結構。 本文藉由與產業專家的深入訪談得知目前既有企業對於新科技尚未開始準備，著實也驗證了Christensen（2005）提過主流企業常常因為過度著重現有技術，而忽略突破性科技的存在。最後，本文建議既有電源供應器產業應多留意突破性科技的入侵且適時跨入新科技，才能在突破性科技崛起時做好準備。 / The main purpose of this research is to examine the potential of disruptive innovation on the power supply industry. This article investigates the definitions and the classifications of innovation by various scholars. It identifies sustaining innovation with its high-end encroachment and disruptive innovation with its three approaches of low-end encroachment which are immediate, fringe-market, and detached-market. This article reviews the power supply industry and its technology, applications, market status, supply chains and then investigates the wireless charging industry and its technologies, evolutions, standards, and market opportunities. To identify the potential of wireless charging becoming disruptive technology, the article refers to the three-step framework of Schmidt (2008) to assess the potential diffusion pattern. The primary attribute of the incumbent is the charging time whereas the primary attribute of new technology is its wireless convenience. The results classify wireless charging as a low-end detached-market encroachment. The current and new products initially sell to the two opposite ends of the market and the highest willingness to pay for each market in the beginning are different, which are “detached “from one another. Over time, charging time would be expected to improve and cost would be expected to decrease, wireless chargers will be more favorable to high-end users of the wired chargers, and eventually current market will be encroached by the new technology. The interviews with incumbents present that current power supply firms have not initiated the development of wireless technology. Companies usually pursue sustaining innovations at the higher tiers of their markets because this is what has historically helped them succeed and they often missed the chances to disruptive innovation. (Christensen, 2005) The results suggest the established organizations to take more efforts to start looking into the disruptive technology so that established organizations will not be displaced by the new firms.

This Master of Applied Science thesis proposes a new design of low power, power factor corrected (PFC), power supplies. By lifting the hold up time restriction for devices that have a battery built in, the energy storage elements of the converter can be reduced, permitting a small and inexpensive power converter to be built. In addition, a new control technique for controlling cascaded converters is presented, named duty mode control (DMC). Its advantages are shown through simulations. The system was proven using a prototype developed in the laboratory designed for a universal ac input voltage (85 - 265VRMS at 50 - 60Hz) and a 40W output at 12V. It consisted of two interleaved phases sensed and digitally controlled on the isolated side of the converter. The prototype was able to achieve a power factor of greater than 0.98 for all operating conditions, and input harmonic current distortion well below any set of standards.

This Master of Applied Science thesis proposes a new design of low power, power factor corrected (PFC), power supplies. By lifting the hold up time restriction for devices that have a battery built in, the energy storage elements of the converter can be reduced, permitting a small and inexpensive power converter to be built. In addition, a new control technique for controlling cascaded converters is presented, named duty mode control (DMC). Its advantages are shown through simulations. The system was proven using a prototype developed in the laboratory designed for a universal ac input voltage (85 - 265VRMS at 50 - 60Hz) and a 40W output at 12V. It consisted of two interleaved phases sensed and digitally controlled on the isolated side of the converter. The prototype was able to achieve a power factor of greater than 0.98 for all operating conditions, and input harmonic current distortion well below any set of standards.

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Grid-connected photovoltaic systems with energy storage have features of conventional gridconnected inverters and uninterruptible power supplies. In these systems, all elements, which include photovoltaic generator, batteries, loads and electric grid, are connected to the same equipment named multifunctional photovoltaic converter. As it is a recent technology, there are many research opportunities in this theme, from classifications and standards to specific problems. This study investigates this field in a comprehensive manner, proposing classifications, technical recommendations and a power management strategy. Initially, classifications are proposed considering system configuration and continuity of supply to the loads. In the following, technical recommendations related to grid and load compatibility, as well as safety technical recommendations, are proposed. The last proposal consists on a power management strategy which defines the operation mode of the static converters and system elements as a function of the energy scarcity. Experimental results of the power management are presented in order to validate the proposals. In this way, this thesis contributes to the development of multifunctional photovoltaic converters technology so that the distributed generation becomes more independent of solar availability and can better collaborate with the electric system. / Sistemas fotovoltaicos conectados à rede com armazenamento de energia são aqueles que conjugam características dos inversores conectados à rede convencionais e de fontes ininterruptas de energia. Nesses sistemas, todos os seus elementos, que incluem o gerador fotovoltaico, as baterias, as cargas e a rede elétrica, são conectados a um mesmo equipamento chamado de conversor fotovoltaico multifuncional. Por se tratar de uma tecnologia recente, existem muitas oportunidades de pesquisa inédita no tema, desde premissas e classificações básicas até a solução de problemas mais específicos. Este trabalho investiga o tema de maneira abrangente, propondo classificações, recomendações técnicas e uma estratégia para gerenciamento interno de potência dos conversores fotovoltaicos multifuncionais. Inicialmente, classificações são propostas considerando a configuração do sistema e a continuidade de fornecimento de energia às cargas. A seguir, são propostas recomendações técnicas relacionadas à compatibilidade com a rede e com as cargas, além de recomendações técnicas de segurança, baseando-se em normas existentes. A última proposta consiste em uma estratégia de gerenciamento interno de potência que define os modos de operação dos conversores estáticos e dos elementos do sistema em função da escassez de energia. Resultados experimentais do método proposto para o gerenciamento interno de potências são apresentados com o objetivo de validar as propostas desenvolvidas. Dessa forma, o presente trabalho contribui com o desenvolvimento da tecnologia de conversores fotovoltaicos multifuncionais, para que a geração distribuída de energia elétrica se torne mais independente da disponibilidade solar e possa melhor colaborar com o sistema elétrico.

Work "Providing emergency power nuclear power plant" describes how solving their own consumption nuclear power plant, as emergency power supply is designed and how it should be a solution of known states of emergency, having an immediate impact on the power consumption of their own nuclear power plants. The aim of this thesis is to propose options to strengthen its own emergency power consumption of nuclear power plants, one might say-more resistant to harsh extremes, which could lead to loss of employment, reserve and emergency power, that is the condition called Station Black Out (SBO) - total loss of power. The work also includes calculations of short-circuit ratios emergency resources considered as strengthening, as well as the calculation of acceleration heaviest drive and a summary of the overall impacts of the proposed hardening.

Electrical energy plays an indispensable role in our contemporary society. However, we mostly realize its position in agriculture in a situation which often already entails irreversible consequences. Therefore, the thesis aims to assess the consequences of power blackout on agricultural farming. In connection with the selected objective, a question arises whether long-term power blackouts also constitute a serious threat to agricultural farms of South Bohemia? The theoretical part briefly describes electrical energy, its production and method of transmission. It also includes basic elements of the power system including its stability and safety. The chapter also acquaints the reader with the critical infrastructure of the Czech Republic and its legislative base. Then, it globally analyzes the term blackout.Given the topic of the thesis, it is necessary to mention the valuable work of the integrated rescue system which in addition to the basic obligations to ensure the protection of human life and property is required to provide missions to rescue animals in emergency situations. Finally, this chapter deals with the application of electrical energy in agriculture, including the characteristics of surveyed farms and a high degree of automation used in farming.The research part is based on the search of the current state of selected agricultural farms. The research was focused on the South Bohemian Region which makes no exception in relation to this issue. Used for the research was a qualitative method of data collection with the information obtained through the techniques of controlled interviews and the secondary analysis of data provided by competent employees of farms in South Bohemia. The results are then outlined in two planes. During recent years, breeding stations have been completely renovated, especially in the section of technological processes. Modern electronic devices which include e.g. automated milking, feeding, suction and washing equipment, heating of service water and heating, should ensure trouble-free operation in such farms. However, what the vast majority of farms is not adequately prepared for is to ensure their smooth operation even during a failure of the electrical system. A number of farms do not have an alternate source of electrical energy. The percentage of self-sufficient farms having on its premises a pumping station that can supply the local diesel-aggregate, is also negligible. Moreover, in case of a diesel-aggregate failure, no alternative source is available. A crucial problem arises in the category of poultry. The animals are situated in large-volume halls where all processes are controlled by fully automated control systems. An alternative source of electrical energy is a crucial element needed to ensure normal operation of the farms. Unless the established criteria are in compliance (ventilation, lighting, etc.), reaction of the animals becomes evident within tens of minutes. Any deviation results in rapid loss of animals. It is assumed that the resulting data will be used both for research purposes in the area of secondary impacts in case of electrical system failures and for objective assessment of the effectiveness in farming security within the current methods. The purpose is to educate the above entities.

This master thesis presents the development of an auxiliary power supply to provide energy to sensors, gate drivers, instrumentation circuits and control of a three-stage Solid State Transformer (SST). These devices require an insulated power supply of ±15V and 5V. For reason of reliability and modularity, a distributed auxiliary source is proposed. Thus, it is necessary a power supply to provide energy to the low voltage (LV) side and another to the medium voltage (MV) side. With this proposal, the auxiliary power supply does not need to have the same galvanic insulation of the SST, 25kV. However, a local power supply must operate at high voltage levels and, consequently, contain a high step-down voltage gain. Relative to LV side, the most generally used topologies as an auxiliary power supply are discussed. However, these topologies cannot be used at the MV converters, due to the high voltage stress levels involved. A study of topologies used on medium and high voltage and which enable to reach a high step-down voltage gain is realized, and two interesting topologies for this application were found. One of them uses a Flying capacitor converter connected in cascade with a Double-Ended Flyback converter. The Flying capacitor converter lowers the DC bus voltage in a controlled manner to low voltage levels. So the Double-ended Flyback converter operates in LV and provides the insulated outputs to command circuits of SST. The other topology is a unidirectional four-level NPC converter operating as Double-ended Flyback converter. For this case, a modulation strategy that allows the converter to reach a high step-down voltage gain was also proposed. These topologies were evaluated and the one which showed the best result was the four-level Double-ended Flyback converter. This converter was implemented and the experimental results prove to be effective. For the LV side, a Half-bridge LLC resonant converter as auxiliary power supply was used. This converter operates in ZVS and performs the output voltage regulation through the operating frequency variation. The experimental results of this converter are also presented. / Este trabalho de mestrado apresenta o desenvolvimento de fontes auxiliares para alimentar sensores, circuitos de comando, instrumentação e o controle de um Transformador de Estado Sólido (SST) de três estágios. Estes dispositivos necessitam de alimentação isolada com tensões de ±15V e 5V e por questões de confiabilidade e modularidade, propõe-se a utilização de fontes auxiliares distribuídas. Assim, emprega-se uma fonte auxiliar para alimentar o lado de média tensão (MT) e outra para alimentar o lado de baixa tensão (BT). Com essa proposta, as fontes auxiliares não necessitam ter a mesma isolação galvânica do SST, 25kV. Entretanto, uma das fontes locais deve operar em níveis de tensão elevados e, por consequência, apresentar baixo ganho estático. No lado de BT, as principais topologias normalmente utilizadas como fonte auxiliar são discutidas. No entanto, devido aos altos níveis de tensão envolvidos, estas topologias não podem ser aplicadas ao conversor que opera em MT. Um estudo sobre topologias aplicadas a média tensão e que possibilitam alcançar um baixo ganho estático é realizado, sendo que duas topologias se mostram interessantes para esta aplicação. Uma consiste na utilização de um conversor de capacitores flutuantes conectado em cascata com um conversor Double-Ended Flyback. O conversor de capacitores flutuantes rebaixa a tensão do barramento CC, de forma controlada, para baixa tensão. Assim o Double-Ended Flyback opera em BT e fornece as saídas isoladas para alimentar os circuitos de comando do SST. A outra topologia trata-se de um conversor NPC de quatro níveis unidirecional operando como conversor Double-Ended Flyback. Para este caso, também foi proposta uma estratégia de modulação que permite o conversor alcançar o baixo ganho estático. Essas topologias foram avaliadas, apresentando melhor resultado a esta aplicação o conversor Double-ended Flyback de quatro níveis, conforme será demonstrado neste trabalho. Esse conversor foi implementado e os resultados experimentais comprovam o seu funcionamento. Para a fonte do lado de BT utilizou-se um conversor Half-Bridge LLC ressonante que opera em ZVS e realiza a regulação da tensão de saída pela variação da frequência de operação. Os resultados experimentais deste conversor também são apresentados.

Este trabalho apresenta o projeto e a implementação prática de um método completo para ser utilizado na conexão de UPSs monofásicos em paralelo. Existe um algoritmo que executa o droop de fase/frequência, e um novo método que trabalha com e sem comunicação de dados entre os inversores. Quando a comunicação está ativa, um novo algoritmo é utilizado, inserindo um resistência virtual variável, junto com o compartilhamento de potência ativa, obtendo um baixo valor de THD (Total Harmonic Distortion) na tensão de saída e bom compartilhamento de potência. Quando a comunicação de dados não funciona, uma resistência virtual constante é inserida, aumentando a THD de saída com carga não-linear, mas ainda proporcionando um bom compartilhamento de potência ativa. A vantagem é poder obter um bom desempenho quando a comunicação de dados está operando, mas, no caso de sua falha, o sistema ainda funciona, proporcionando maior confiabilidade. A implementação possui um algoritmo de emulação de carga eletrônica, com o propósito de executar testes de produção, baseado no mesmo algoritmo de paralelismo, apenas mudando algumas variáveis. / This work presents the design and experimental implementation of a complete paralleling method to be used for parallel single-phase UPSs connection. There is a algorithm that performs a phase/frequency droop, and a new method to work with or without data communication among the inverters. When communication is working, a new algorithm is used, inserting a variable virtual resistance in the output, along with active power sharing, obtaining a low output voltage THD (Total Harmonic Distortion) value and good power sharing. Without communication a constant virtual resistance is inserted, increasing the output THD with non-linear load, but still allowing a good active power sharing. The advantage is to obtain a good performance operation with communication, but, in case of communication failure, the system still works providing more reliability. The implementation have a electronic load emulation algorithm, with purpose to execute factory tests, based in the same parallelism algorithm, just changing some variables.

Este trabalho apresenta o projeto e a implementação prática de um método completo para ser utilizado na conexão de UPSs monofásicos em paralelo. Existe um algoritmo que executa o droop de fase/frequência, e um novo método que trabalha com e sem comunicação de dados entre os inversores. Quando a comunicação está ativa, um novo algoritmo é utilizado, inserindo um resistência virtual variável, junto com o compartilhamento de potência ativa, obtendo um baixo valor de THD (Total Harmonic Distortion) na tensão de saída e bom compartilhamento de potência. Quando a comunicação de dados não funciona, uma resistência virtual constante é inserida, aumentando a THD de saída com carga não-linear, mas ainda proporcionando um bom compartilhamento de potência ativa. A vantagem é poder obter um bom desempenho quando a comunicação de dados está operando, mas, no caso de sua falha, o sistema ainda funciona, proporcionando maior confiabilidade. A implementação possui um algoritmo de emulação de carga eletrônica, com o propósito de executar testes de produção, baseado no mesmo algoritmo de paralelismo, apenas mudando algumas variáveis. / This work presents the design and experimental implementation of a complete paralleling method to be used for parallel single-phase UPSs connection. There is a algorithm that performs a phase/frequency droop, and a new method to work with or without data communication among the inverters. When communication is working, a new algorithm is used, inserting a variable virtual resistance in the output, along with active power sharing, obtaining a low output voltage THD (Total Harmonic Distortion) value and good power sharing. Without communication a constant virtual resistance is inserted, increasing the output THD with non-linear load, but still allowing a good active power sharing. The advantage is to obtain a good performance operation with communication, but, in case of communication failure, the system still works providing more reliability. The implementation have a electronic load emulation algorithm, with purpose to execute factory tests, based in the same parallelism algorithm, just changing some variables.

The theme of the master´s thesis is design a microphone preamplifier which uses vacuum tube as a main amplifying element. Part of the work is theoretical assumptions for the optimal design and implementation of peripheral involvement, comparing the properties of components used and the resulting parameters of modeled device. The thesis also includes a proposal of the source unit for supplying all parts of the preamplifier. The results are accompanied by circuit simulations and laboratory measurements of the main parameters of the designed device.