This thesis presents a novel Resonant Switched-Capacitor Converter with Multiple Resonant Frequencies, abbreviated as MRSCC for both high density and efficiency non-isolated large step-down Intermediate Bus Converter (IBC). Conventional Resonant Switched-Capacitor Converter (RSCC) proposed by Shoyama and its high voltage conversion ratio derivation such as Switched-Tank Converter (STC) by Jiang and li employ half sinusoidal-current charge transfer method between capacitors to achieve high efficiency and density operation by adding a small resonant inductor in series to pure switched-capacitor converter's (SCC) flying capacitor. By operating switching frequency to be the same as its resonant frequency, RSCC achieves zero-current turn off operation, however, this cause RSCC and its derivation suffer from component variation issue for high-volume adoption. Derived from RSCC, MRSCC adds additional high frequency resonant component, operates only during its dead-time, by adding small capacitor in parallel to RSCC's resonant inductor. By operating switching frequency higher than its main resonant frequency, MRSCC utilizes double chopped half-sinusoidal current charge transfer method between capacitors to further improve efficiency. In addition, operating switching frequency consistently higher than its resonant frequency, MRSCC provides high immunity towards component variation, making it and its derivation viable for high-volume adoption. / MS / Following the recent trend, most internet services are moving towards cloud computing. Large data applications and growing popularity of cloud computing require hyperscale data centers and it will continue to grow rapidly in the next few years to keep up with the demand [4]. These cutting-edge data centers will require higher performance multi-core CPU and GPU installations which translates to higher power consumption. From 10MWatts of power, typical data centers deliver only half of this power to the computing load which includes processors, memory and drives. Unfortunately, the rest goes to losses in power conversion, distribution and cooling [5]. Industry members look into increasing backplane voltage from 12V to 48V in order to reduce distribution loss. This thesis proposes a novel Resonant Switched-Capacitor Converter using Multiple Resonant Frequencies to accommodate this increase of backplane voltage.

L’apparition de convertisseurs multicellulaires parallèles entrelacés et magnétiquement couplés a conduit ces dernières années à améliorer les performances des convertisseurs (densité de puissance, efficacité, dynamique,...). Il existe plusieurs topologies d’entrelacement qui utilisent des Transformateurs Interphases. L’objectif principal de cette étude est de trouver parmi ces topologies celles qui sont les mieux adaptées à un contexte d’intégration d’électronique de puissance pour minimiser la taille et réduire les pertes. Une première étape de modélisation a permis d’effectuer une étude comparative de quelques topologies. Un procédé de permutation des phases d’alimentation a été présenté afin de réduire les ondulations du courant de phases et les pertes ohmiques. Les résultats obtenus valident qualitativement l’avantage de la solution retenue par rapport à la solution standard. Enfin, la réalisation pratique d’un prototype de convertisseur modulaire utilisant des Transformateurs Inter-phases est abordé. Il s’agit d’un régulateur chargé d’alimenter les microprocesseurs (1,2V/100A) (Voltage Regulator Module (VRM)) à 5 modules. Les résultats expérimentaux montrent l’avantage de l’utilisation des Transformateurs Inter-phases par rapport à la solution classique / During the last years, using coupled parallel interleaved converters enhances converters performances (power density, efficiency, transient response,...). There are several possible interleaved coupled topologies that use Inter-phases Transformers. The main objective of this study is to find among these topologies the best adapted configuration in a context of power electronics integration in order to minimize converter size and to reduce losses. A model is proposed to compare some topologies. An optimal modified sequence of phase order to reduce current ripple and ohmic losses is presented. The obtained results validate the advantage of the coupled solution compared to the standard solution. At last, the implementation of a modular power converter using Inter-phases Transformers is shown. It is a Voltage Regulator Module (1,2V/100A) that consists of five identical modules. Experimental results show the advantage of using Inter-phases Transformers compared to conventional solution

Este trabalho apresenta uma estratégia para realizar o controle de tensão em um sistema de distribuição de energia elétrica dotado de comutadores de tap sob carga. Será investigada a aplicação de sistemas inteligentes para tornar os relés reguladores de tensão mais flexíveis. A inserção de módulos inteligentes em relés reguladores de tensão convencionais irá permitir um melhor aproveitamento das funcionalidades já existentes destes dispositivos. Ainda como foco do estudo, pretende-se atuar apenas na subestação de distribuição, realizando medições no barramento secundário e tomando medidas de controle também neste barramento. A capacidade dos sistemas fuzzy em tratar informações incertas, bem como sua potencial aplicabilidade em problemas tendo comportamentos não previsíveis, permitiram a criação de uma estratégia de controle de tensão que atende todas as regulamentações dos órgãos fiscalizadores e, também, os anseios das concessionárias de distribuição de energia elétrica devido aos resultados promissores obtidos em simulação com dados reais das subestações. / This work presents an approach to voltage control in power distribution systems with load tap changers. Intelligent approaches are studied and applied in voltage regulator relay in order to improve the voltage profiles of the system. The proposal of this work is the addition of fuzzy modules in the conventional voltage regulator relays, which allows the exploration of the main functionalities already implemented in such devices. The adaptive fuzzy voltage regulator relay controls the voltage in the distribution substation, monitoring electrical variables and performing the regulation on secondary bus based on the results provided by the fuzzy modules, which are capable to take into account the voltage profile standards for distribution systems as well as operational interests defined by electrical distribution companies. Simulation results using real data from substations are presented to validate the proposed approach.

Present day electrical equipment is rapidly becoming more and more sensitive to power quality problems, especially voltage sags. Various voltage sag correction devices are avaliable. This thesis analyzes a two-switch, single-phase electronic voltage regulator for correcting voltage sags. The theory of this voltage regulator has been investigated. An analytical method for sizing the energy storage capacitors has been established. The voltage regulator has been modeled and its steady-state and dynamic behavior has been studied by means of detailed computer simulations. A 220-V, 50-Hz, 1-kW rated regulator has been designed, simulated, and built. The results on the performance of voltage regulator and conclusions are also given.

The new regulations in the electric sector utilities have have requested greater efficiency and quality both in terms of continuity and in conformity of the energy supplied. Electrical equipments quality, efficiency and useful life depend directly of the power quality supplied. In addition to operation of equipments, supply of energy within the limits must be appropriate for the economic development of regions attended. Considering these factors, to improve quality and ensure conformity of the voltage levels over the distribution networks, the companies are investing in improvements in the system, equipment, voltage regulators and exchange of the conductors and building of new feeders and / or substations. Nowadays due to availability of computational tools and algorithms that allow the estimation of state variables at each point of distribution feeders it is possible to evaluate and plan actions for improvement in the system with more correct. But the improvements planned for the primary network, aiming to reduce the voltage drop and make the system more robust, reflecting the voltage levels in the secondary network and therefore require simultaneous actions to enable the benefits of the study are obtained . In this context, this work objective is to develop a methodology that allows the definition of TAP's appropriate for each distribution transformer, grouping them in TAP zones, together with an algorithm that defines the settings of voltage regulators, taking into consideration not only the primary desired voltage, but also its impact on distribution transformers. This methodology can be used on power utilities for power assisting in the planning and operation of the system. The work is divided into 7 chapters dealing respectively: review, steady state voltage levels and means of control applied in distribution networks, defining the TAP zones of processors, defining the parameters of adjustment of voltage regulators, integrated assessment of the voltage regulators and TAP zones, the author's contributions and considerations on the methodology presented. / As novas regulamentações do setor elétrico têm solicitado das concessionárias uma maior eficiência e qualidade tanto em termos de continuidade como na conformidade da energia fornecida. A qualidade, eficiência e vida útil dos aparelhos elétricos dependem diretamente da qualidade da energia fornecida. Além do funcionamento dos equipamentos, o fornecimento da energia dentro dos limites adequados é necessário para o desenvolvimento econômico das regiões atendidas. Diante desses fatores, a fim de melhorar a qualidade e garantir a conformidade dos níveis de tensão ao longo das redes de distribuição, as empresas distribuidoras investem em melhorias no sistema, equipamentos reguladores de tensão, recondutoramento, construção de novos alimentadores e/ou subestações. Atualmente graças a disponibilidade de ferramentas computacionais e algoritmos que permitem estimar as variáveis de estado em cada ponto dos alimentadores de distribuição torna-se possível avaliar e planejar ações de melhorias no sistema com maior assertividade. Porém as melhorias planejadas para a rede primária, com o objetivo de reduzir a queda de tensão e tornar o sistema mais robusto, refletem nos níveis de tensão da rede secundária e por isso necessitam de ações simultâneas para possibilitar que os benefícios do estudo realizado sejam obtidos. Nesse contexto, o presente trabalho tem a proposta de desenvolver uma metodologia que permita a definição dos TAP s adequados para cada transformador de distribuição, agrupando-os em zonas de TAP, juntamente com um algoritmo que defina os ajustes dos reguladores de tensão levando em consideração não somente a tensão primária desejada, mas também seu impacto nos transformadores de distribuição. Esta metodologia poderá ser aplicada nas empresas distribuidoras de energia elétrica auxiliando nas áreas de planejamento e operação do sistema. O trabalho está divido em 7 capítulos tratando respectivamente de: revisão bibliográfica; níveis de tensão e meios de controle aplicados nas redes de distribuição; definição das zonas de TAP dos transformadores; definição dos parâmetros de ajuste dos reguladores de tensão; avaliação integrada dos reguladores de tensão e zonas de TAP; contribuições e considerações do autor a respeito da metodologia apresentada.

Este trabalho apresenta uma estratégia para realizar o controle de tensão em um sistema de distribuição de energia elétrica dotado de comutadores de tap sob carga. Será investigada a aplicação de sistemas inteligentes para tornar os relés reguladores de tensão mais flexíveis. A inserção de módulos inteligentes em relés reguladores de tensão convencionais irá permitir um melhor aproveitamento das funcionalidades já existentes destes dispositivos. Ainda como foco do estudo, pretende-se atuar apenas na subestação de distribuição, realizando medições no barramento secundário e tomando medidas de controle também neste barramento. A capacidade dos sistemas fuzzy em tratar informações incertas, bem como sua potencial aplicabilidade em problemas tendo comportamentos não previsíveis, permitiram a criação de uma estratégia de controle de tensão que atende todas as regulamentações dos órgãos fiscalizadores e, também, os anseios das concessionárias de distribuição de energia elétrica devido aos resultados promissores obtidos em simulação com dados reais das subestações. / This work presents an approach to voltage control in power distribution systems with load tap changers. Intelligent approaches are studied and applied in voltage regulator relay in order to improve the voltage profiles of the system. The proposal of this work is the addition of fuzzy modules in the conventional voltage regulator relays, which allows the exploration of the main functionalities already implemented in such devices. The adaptive fuzzy voltage regulator relay controls the voltage in the distribution substation, monitoring electrical variables and performing the regulation on secondary bus based on the results provided by the fuzzy modules, which are capable to take into account the voltage profile standards for distribution systems as well as operational interests defined by electrical distribution companies. Simulation results using real data from substations are presented to validate the proposed approach.

abstract: Power management integrated circuit (PMIC) design is a key module in almost all electronics around us such as Phones, Tablets, Computers, Laptop, Electric vehicles, etc. The on-chip loads such as microprocessors cores, memories, Analog/RF, etc. requires multiple supply voltage domains. Providing these supply voltages from off-chip voltage regulators will increase the overall system cost and limits the performance due to the board and package parasitics. Therefore, an on-chip fully integrated voltage regulator (FIVR) is required. The dissertation presents a topology for a fully integrated power stage in a DC-DC buck converter achieving a high-power density and a time-domain hysteresis based highly integrated buck converter. A multi-phase time-domain comparator is proposed in this work for implementing the hysteresis control, thereby achieving a process scaling friendly highly digital design. A higher-order LC notch filter along with a flying capacitor which couples the input and output voltage ripple is implemented. The power stage operates at 500 MHz and can deliver a maximum power of 1.0 W and load current of 1.67 A, while occupying 1.21 mm2 active die area. Thus achieving a power density of 0.867 W/mm2 and current density of 1.377 A/mm2. The peak efficiency obtained is 71% at 780 mA of load current. The power stage with the additional off-chip LC is utilized to design a highly integrated current mode hysteretic buck converter operating at 180 MHz. It achieves 20 ns of settling and 2-5 ns of rise/fall time for reference tracking. The second part of the dissertation discusses an integrated low voltage switched-capacitor based power sensor, to measure the output power of a DC-DC boost converter. This approach results in a lower complexity, area, power consumption, and a lower component count for the overall PV MPPT system. Designed in a 180 nm CMOS process, the circuit can operate with a supply voltage of 1.8 V. It achieves a power sense accuracy of 7.6%, occupies a die area of 0.0519 mm2, and consumes 0.748 mW of power. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019

X-ray fluorescence is a fast, non-destructive method to measure substances. This method can be used to detect elements in an environmental sample for elemental analysis. Commercially available XRF units exists, but their scope of application is limited. In the university lab, a more generalized XRF setup is available. At present, the environmental samples can only be sampled and brought into the laboratory for testing. During the sample transport, some changes may occur in the sample. At the same time, in the laboratory test, the sample parameters in the current environment cannot be obtained in real time. So we consider the design of a battery power supply. At the same time, there are different ways to reduce power consumption. This paper considers usability and reduction of power consumption in various aspects to bring the X-ray source and spectrometer to the environment for element detection. We have to choose the battery to achieve the best length of operating time. The system design includes the selection of a DC/DC converter boost regulator to adjust the battery output to meet the input voltage requirements of the X-ray source and of the X-ray spectrometer.

No description available.

The future voltage regulator module (VRM) challenges of high bandwidth control with fast transient response, high current output, simple implementation, and efficient 48V solution are tackled in this dissertation. With the push for control bandwidth to meet design specifications for microprocessor VRM with larger and faster load transients, control can be saturated and lost for a significant period of time during transient. During this time, undesirable transient responses such as large undershoot and ringback occurs. Due to the loss of control, the existing tools to study the dynamic behavior of the system, such as small signal model, are insufficient to analyze the behavior of the system during this time. In order to have a better understanding of the system dynamic performance, the operation the VRM is analyzed in the state-plane for a clear visual understanding of the steady-state and transient behaviors. Using the state-plane, a simplified state-plane trajectory control is proposed for constant on-time (COT) control to achieve the best transient possible for applications with adaptive voltage positioning (AVP). When the COT control is lost during a load step-up transient, the state-plane trajectory control will extend on-time to provide the a near optimal transient response. By observing the COT control law in the state-plane, a simplified state-plane trajectory control with analog implementation is proposed to achieve the best transient possible with smooth transitions in and out of the steady-state COT control. The concept of the simplified state-plane trajectory control is then extended to multiphase COT. For multiphase operation, additional operating behavior, such as phase overlapping during transient and interleaving during steady-state, need to be taken into consideration to design the desired state-plane trajectory control. A simple state-plane trajectory control with improved Ton extension is proposed and verified using multiphase COT control. After tackling the state-plane trajectory control for current mode COT, the idea is then extended to V2 COT. V2 COT is a more advanced current mode control which requires a more advanced state-plane trajectory control to COT. By calculating the intersection of the extended on-stage trajectory during transient and the ideal off trajectory in the form of a current limiting wall, a near optimal transient response can be achieved. For V2 COT with state-plane trajectory control, implementations using inductor vs. capacitor current, effect of component tolerance, and effect of IC delay are studied. The proposed state-plane trajectory control is then extended to enhanced V2 COT. Aside from tackling existing VRM challenges, the future datacenter 48V VRM challenge of a high efficiency, high power density solution to meet the VRM specifications is studied. The sigma converter is proposed for the 48V VRM solution due to exhibition of high efficiency and high-power density from hardware evaluation. An accurate model for the sigma converter is derived using the new modeling approach of modularizing the small signal components. Using the proposed model, the sigma converter is shown to naturally have very low output impedance, making the sigma converter suitable for microprocessor applications. The sigma converter is designed and optimized to achieve AVP and very fast transient response using both voltage-mode and current-mode controls. / Doctor of Philosophy / Microprocessors, such as central processing unit (CPU) and graphics processing unit (GPU) are the basis of today's electronics. In the recent decades, the demand for more powerful and faster data processing lead to a significant increase in power consumption by these microprocessors. Even with the introduction of multi-core processors and adaptive voltage positioning (AVP) to reduce the average power provided by the power supplies, the microprocessor can still draw a large amount of instantaneous power in a short period of time. With the microprocessors demanding high amount of current at fast slew-rate, the challenges for the next generation of microprocessor power supply, or voltage regulator modules (VRM), are fast response speed to ensure proper operation of the microprocessors, and high efficiency VRM to minimize the overall system power consumption. The challenge of a VRM with fast response speed is tackled first. To meet the AVP and transient requirements of microprocessor, the VR need to utilize high-bandwidth control methods. Of the control methods used by the industry, high control bandwidth can be easily achieved using constant on-time (COT) control. With the ever-increasing output current level and transient slew-rate requirements, COT control can saturate and lose its steady-state control for a period of time during load step-up transient. During this time, the system will operate with a fixed frequency control until COT control is recovered. Although the method is widely used in the industry, the method is too slow to meet the transient requirements. Many state-of-art methods have been proposed to resolve the load step-up transient issue of COT. However, of the methods proposed, it is difficult to optimize the transient improvement while having a simple analog implementation to ensure a fast response for the wide operating range and aggressive transient conditions observed in microprocessor VRM application. In this dissertation, COT control is studied using the state-plane to provide a clear visual understanding of the transient behavior of the control. Using the state-plane, a state-plane trajectory control is proposed to achieve near optimal load step-up transient response. The concept is then extended to multiphase VRM, which is typically used for high current applications. The state-plane trajectory control concept is then further extended to V2 COT control for VRM without AVP, such as those used by GPU and smartphone CPU. For the proposed state-plane trajectory controls, hardware implementation, evaluation, and experimental results are provided. After tackling the challenge of a VRM with fast response speed, the challenge of an efficient VRM is then tackled. In recent years, a significant amount of research has been put into studying VRM for a power delivery architecture which uses a 48V bus instead of the 12V bus. By using the 48V bus, less redundancy in the power delivery path can greatly increase the overall system efficiency if the VRM stage retains its efficiency. However, the increase in input voltage for the VRM provides an additional challenge to maintain high efficiency for the VRM stage itself. To maintain good efficiency, it is difficult to increase converter switching frequency beyond 300kHz. This limitation on switching frequency will limit the ability to achieve high bandwidth design and fast transient requirements. A 48V VRM using a different topology, the sigma converter, has demonstrated high-efficiency and high-power density, but the converter behavior and control methodology for VRM application is unclear. In this dissertation, the modeling and control of the sigma converter are studied using the proposed small-signal model. By evaluating the proposed small-signal model, the sigma converter can naturally have very low output impedance, making it an ideal candidate for 48V VRM. Then, the design guideline of the sigma converter with current-mode control is provided. With the work discussed in this dissertation, further study of the sigma converter with COT and state-plane trajectory control can be conducted in the future.