Dissertations / Theses on the topic 'Design buck-boost converter'

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.<br>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.

In this thesis a multifunctional DC/DC converter board will be developed for utilization as an educational experiment set in the switched-mode power conversion laboratory of power electronic courses. The board has a generic power-pole structure allowing for easy configuration of various power converter topologies and includes buck, boost, buck-boost, flyback, and forward converter topologies. All the converters can be operated in the open-loop control mode with a switching frequency range of 30-100 kHz and a maximum output power of 20 W. Also the buck converter can be operated in voltage mode control and the buck-boost converter can be operated in peak-current-mode control for the purpose of demonstrating the closed loop control performance of DC/DC converters. The designed board allows for experimentation on the DC/DC converters to observe the macroscopic (steadystate/ dynamic, PWM cycle and low frequency) and microscopic (switching dynamic) behavior of the converters. In the experiments both such characteristics can be clearly observed such that students at basic learning level (involving only the macroscopic behavior), and students at advanced learning level (additionally involving the parasitic effects) can benefit from the experiments. The thesis reviews the switch mode conversion principles, gives the board design and proceeds with the experiments illustrating the capabilities of the experimental system.

This thesis report details the design and construction of non-isolated DC-DC converters to create a Multiple Input Single Output (MISO) converter for combining multiple renewable energy sources into one single output. This MISO uses the four-switch buck-boost topology to output a single 48V from multiple nominal 24V inputs. The MISO converter implements a modular approach to deliver 1800W output power. Each module in the MISO is rated at 600W and they share the output power equally. Hardware results show that the converter produces 1800W of output power from three sources with 96.4% efficiency. Each module also demonstrates equal sharing feature of the MISO converter.

Electrical energy is used at approximately the rate of 15 Terawatts world-wide. Generating this much energy has become a primary concern for all nations. There are many ways of generating energy among which the most commonly used are non-renewable and will extinct much sooner than expected. Very active research is going on both to increase the use of renewable energy sources and to use the available energy with more efficiency. Among these sources, solar energy is being considered as the most abundant and has received high attention. The mobile phone has become one of the basic needs of modern life, with almost every human being having one.Individually a mobile phone consumes little power but collectively this becomes very large. This consideration motivated the research undertaken in this masters thesis. The objective of this thesis is to design a model for solar power based charging circuits for mobile phone using Simulink(R). This thesis explains a design procedure of solar power based mobile charger circuit using Simulink(R) which includes the models for the photo-voltaic array, maximum power point tracker, pulse width modulator, DC-DC converter and a battery. The first part of the thesis concentrates on electron level behavior of a solar cell, its structure and its electrical model.The second part is to design an array of solar cells to generate the desired output. Finally, the third part is to design a DC-DC converter which can stabilize and provide the required input to the battery with the help of the maximum power point tracker and pulse width modulation. The obtained DC-DC converter is adjustable to meet the requirements of the battery. This design is aimed at charging a lithium ion battery with nominal voltage of 3.7 V, which can be taken as baseline to charge different types of batteries with different nominal voltages.

La croissante demande d'énergie électrique a conduit à la conception de systèmes électriques de grande complexité où les combustibles fossiles constituent la principale source d'énergie. Néanmoins, les préoccupations environnementales poussent à un changement majeur dans les pratiques de production d'électricité, avec un passage marqué des énergies fossiles aux énergies renouvelables et des architectures centralisées à distribuées. Les problèmes de stabilité dus à la présence de ce qu'on appelle les Charges à Puissance Constante (CPLs) constituent l’un des principaux défis auxquels sont confrontés les systèmes électriques distribués. On sait que ces charges, que l’on trouve couramment dans les installations de technologie de l’information et de la communication, réduisent l’amortissement effectif des circuits qui les alimentent, ce qui peut provoquer des oscillations de tension, voire une chute. Dans cette thèse, les principales contributions sont centrées sur la compréhension et la résolution de divers problèmes rencontrés dans l'analyse et le contrôle de systèmes électriques contenant des CPLs. Les contributions sont énumérées comme suit. (i) Des conditions simplement vérifiables sont proposées pour certifier la non existence d'états en régime permanent pour des réseaux multi-ports, à courant alternatif avec une distribution de CPLs. Ces conditions, qui reposent sur les inégalités matricielles linéaires, permettent d’écarter les valeurs des puissances des charges qui produiraient certainement un effondrement de la tension sur l’ensemble du réseau. (ii) Pour des modèles généraux de certains systèmes électriques modernes, y compris les réseaux de transmission à courant continu haute tension et les microréseaux, il est montré que, si des équilibres existent, il existe un équilibre caractéristique à haute tension qui domine tous les autres. En outre, dans le cas des systèmes d'alimentation en courant alternatif sous l'hypothèse de découplage standard, cet équilibre caractéristique s'avère stable à long terme. (iii) Une classe de systèmes port-Hamiltoniens, dans laquelle les variables de contrôle agissent directement sur l'équation du balance de puissance, est explorée. Il est démontré que ces systèmes sont décalés de manière passive lorsque leurs trajectoires sont contraintes à des ensembles facilement définissables. Ces dernières propriétés sont exploitées pour analyser la stabilité de leurs équilibres intrinsèquement non nuls. Il a également été montré que la stabilité des réseaux électriques à courant continu multiports et des générateurs synchrones, tous deux connectés à des CPLs, peuvent naturellement être étudiée avec le cadre proposé. (iv) Le problème de la régulation de la tension de sortie du convertisseur buck-boost alimentant une CPL non connu est résolu. L'un des principaux obstacles à la conception de commandes linéaires classiques provient du fait que le modèle du système est de phase non minimale par rapport à chacune de ses variables d'état. Cette thèse rapporte un contrôleur adaptatif non linéaire capable de rendre un équilibre souhaité asymptotiquement stable; de plus, une estimation de la région d'attraction peut être calculée. (v) La dernière contribution concerne l'amortissement actif d'un système d'alimentation de petite taille à courant continu avec une CPL. Au lieu de connecter des éléments passifs peu pratiques et énergétiquement inefficaces au réseau existant, l’ajout d’un convertisseur de puissance contrôlé est exploré. La contribution principale rapportée ici est la conception d'une loi de contrôle non linéaire basée sur l'observateur pour le convertisseur. La nouveauté de la proposition réside dans le fait qu'il n'est pas nécessaire de mesurer le courant électrique du réseau ni la valeur de la CPL, soulignant ainsi son applicabilité pratique. L'efficacité du schéma de contrôle est ensuite validée par des expériences sur un réseau à courant continu réel<br>The continuously increasing demand of electrical energy has led to the conception of power systems of great complexity that may extend even through entire countries. In the vast majority of large-scale power systems the main primary source of energy are fossil fuels. Nonetheless, environmental concerns are pushing a major change in electric energy production practices, with a marked shift from fossil fuels to renewables and from centralized architectures to more distributed ones. One of the main challenges that distributed power systems face are the stability problems arising from the presence of the so-called Constant Power Loads (CPLs). These loads, which are commonly found in information and communication technology facilities, are known to reduce the effective damping of the circuits that energize them, which can cause voltage oscillations or even voltage collapse. In this thesis, the main contributions are focused in understanding and solving diverse problems found in the analysis and control of electrical power systems containing CPLs. The contributions are listed as follows. (i) Simply verifiable conditions are proposed to certify the non existence of steady states in general, multi-port, alternating current (AC) networks with a distributed array of CPLs. These conditions, which are based on Linear Matrix Inequalities, allow to discard the values of the loads' powers that would certainly produce a voltage collapse in the whole network. (ii) For general models of some modern power systems, including High-Voltage Direct Current transmission networks and microgrids, it is shown that if equilibria exist, then there is a characteristic high-voltage equilibrium that dominates, entry-wise, all the other ones. Furthermore, for the case of AC power systems under the standard decoupling assumption, this characteristic equilibrium is shown to be long-term stable. (iii) A class of port-Hamiltonian systems, in which the control variables act directly on the power balance equation, is explored. These systems are shown to be shifted passive when their trajectories are constrained to easily definable sets. The latter properties are exploited to analyze the stability of their---intrinsically non zero---equilibria. It is also shown that the stability of multi-port DC electrical networks and synchronous generators, both with CPLs, can be naturally studied with the proposed framework. (iv) The problem of regulating the output voltage of the versatile DC buck-boost converter feeding an {em unknown} CPL is addressed. One of the main obstacles for conventional linear control design stems from the fact that the system's model is non-minimum phase with respect to each of its state variables. As a possible solution to this problem, this thesis reports a nonlinear, adaptive controller that is able to render a desired equilibrium asymptotically stable; furthermore an estimate of the region of attraction can be computed. (v) The last contribution concerns the active damping of a DC small-scale power system with a CPL. Instead of connecting impractical, energetically inefficient passive elements to the existing network, the addition of a controlled DC-DC power converter is explored. The main contribution reported here is the design of a nonlinear, observer-based control law for the converter. The novelty of the proposal lies in the non necessity of measuring the network's electrical current nor the value of the CPL, highlighting its practical applicability. The effectiveness of the control scheme is further validated through experiments on a real DC network

碩士<br>國立勤益科技大學<br>電子工程系<br>102<br>This paper propose a voltage conversion circuit with feedback control to achieve the buck and boost converters' output stability. In the PWM control circuit, we use TL494 to determine the duty cycle with pulse width modulation(PWM), and design feedback architecture with optical coupler, the feedback signal is supplied to the PWM control circuit, in order to achieve the goal of a stable output. Circuit design proposed in this study, through the experiment of line regulation and load regulation is proved to achieve stable voltage output.

博士<br>國立臺北科技大學<br>電腦與通訊研究所<br>102<br>In this first part of this thesis, a new continuous conduction mode (CCM) low-ripple high-efficiency charge-pump boost converter is presented. Its components include a double voltage charge pump and a low pass LC filter. The voltage boost ratio of the positive low-ripple output voltage of the proposed converter is (1+D) where D is the duty cycle of the control switching signal waveform. Since the energy storage inductor is connected to the power source and the load at all times, the proposed converter always operates in CCM, the transient responses are fast, and the current stress on the output capacitor is reduced and the output voltage ripple is small. In this paper, the operation principles of the CCM low-ripple high-efficiency charge-pump boost converter are described in detail. Its circuitry is designed and implemented with a TSMC 0.35µm CMOS processes whose operation frequency is 1MHz. The circuitry is simple and the power conversion efficiency is up to 90.95%, and the transient response is only 7µs. In this second part of this thesis, a fast transient response flying-capacitor buck-boost converter is proposed to improve the efficiency of conventional switched-capacitor converters. The voltage boost ratio of the proposed converter is 2D, where D is the duty cycle of the switching signal waveform. The behavior of the proposed converter is similar to a conventional synchronous-rectified buck converter, thus the stability of the system is very high. It has positive output voltage, which is different from the negative output voltage of a conventional buck–boost converter. Furthermore, the proposed structure utilizes pseudo-current dynamic acceleration techniques to achieve fast transient response when load changes between heavy load and light load. The switching frequency of the proposed converter is 1 MHz for 3.3V input and 1.0V-4.5V output range application. Experiment results show that the proposed scheme improves the transient response to within 2μs and the total power conversion efficiency can be as high as 89.66%. The proposed converter has been realized by a 2P4M CMOS chip by 0.35μm fabrication process with total chip size of about 1.5 mm × 1.5 mm, PADs included.

碩士<br>國立雲林科技大學<br>電子工程系<br>108<br>With the change of times, the speed of technological progress is changing rapidly, and the utilization rate of Internet of Things devices is increasing year by year. At present, the wireless sensing nodes installed outdoors usually have both energy collection and storage devices, thereby reducing reliance on the transmission lines to increase the elasticity of the device environment. In order to provide the power supply for such devices and to manage the charge and discharge of the battery at the same time, the multi-input-multi-output (MIMO) power management IC is often used in the system. Therefore, this thesis proposes the use of 0.18-μm CMOS power management IC, combined with advanced RISC Machine (ARM) implementation, in a mixed signal design with the cell-based ARM processor circuit synthesis, and the required analog circuit is completed using full-custom and integrated into the digital circuit on the same chip. The proposed CDL-PWM can save power and area, compared with the previous design, it can save 31.1% of power at D=50% and 65.3% power when D=0%. The imbedded microprocessor circuit also achieves A) program-controlled output to save the cost of redesigning the circuit, B) simultaneously processing sensing information without the need for additional computing units, and C) scanning the operating frequency to achieve maximum conversion efficiency. The smart programmable buck-boost converter is implemented based on TSMC 180 nm Mixed Signal RF General Purpose Process (T18). System simulation can achieve both a stable 1.8V battery voltage and 0.7 to 1.2V programmable voltage at the same time at input range of 0.9 to 3.3V, with a maximum efficiency of 85%.

碩士<br>國立臺北科技大學<br>電腦與通訊研究所<br>99<br>The first part which is a low-voltage positive buck-boost converter using average- current-controlled techniques is proposed in this thesis. This circuit is different from the traditional buck-boost converter, the shortcoming which is output negative voltage has improved on traditional buck-boost converter. Moreover, the average-current-controlled circuit does not need to use slope compensation technique. The advantages of the low-voltage operational amplifier are lower power dynamic consumption and low supply voltage operation. The proposed low-voltage positive buck-boost converter using the active-current-sensing circuit and average-current-controlled circuit techniques can work stably without slope compensation even when the duty cycle is higher than 50%. The proposed design circuit has been fabricated with TSMC 0.35μm CMOS 2P4M processe, the total chip area is 2.46 x 2.47mm2 (with PADs). The supply voltage is 1.5V, and the regulated output voltage range is from 0.8V-3.3V. Switching frequency is 1 MHz. The second part of this thesis is a high-efficiency positive buck-boost converter with mode-select circuit and feedforward techniques is proposed. Four power transistors which produces more conduction and more switching losses turn on or off when positive buck-boost converter operates in buck-boost mode. Utilizing mode-select circuit can decrease this problem and let positive buck-boost converter in buck, buck-boost or boost mode. By adding feedforward techniques, the proposed circuit can improve transient respones when supply voltage changing. The proposed design circuit has been fabricated with TSMC 0.35μm CMOS 2P4M processe, the total chip area is 2.59 x 2.74mm2 (with PADs). The output voltage is 3.3V, and the regulated supply voltage range is from 5V-2.5V. Switching frequency is 500 kHz.

碩士<br>國立臺北大學<br>電機工程研究所<br>100<br>Multiple voltages are often required for powering many hand-held electronic devices. In such applications, multiple DC-DC converters are often used to convert from a battery to proper multiple output voltages. Each converter usually requires one inductor for the power conversion. Therefore, the multiple inductors used for such application are relatively bulky and a waste of space. In recent years, however, a new class of converters has been reported capable of providing multiple outputs using only single inductor. Therefore, This thesis propose a module using just three power switchers and one compensation with Voltage mode control. These can lower down the loss of the switch, decrease the need of the external components, and has better noise immunity. We use ordered power distribution control (OPDC) which works in continuous conduction mode (CCM) with high efficiency. The DC-DC converter has been implemented in TSMC 0.35-μm 2P4M CMOS process. According to the measurement results, the maximum peak-to-peak output voltage ripple is less than 20mV, and current ranges are between 1mA and 100mA. The DC-DC converter operates in frequency 500 kHz~1MegHz and supplies voltage ranges from 3.6 to 3.8V. The first Buck output voltage can be 1.8V~2.5V and the other Boost output holds 4V~4.6V. The highest efficiency of the circuit can reach up to 94% when the two outputs’ loads are both 50mA.

碩士<br>國立臺灣科技大學<br>電機工程系<br>103<br>In this thesis, a digitally-controlled non-isolated bidirectional buck– boost dc–dc converter is studied and implemented. The proposed converter is capable of operating in all power conditions in buck/boost modes. Through a novel modulation strategy and proper design of the buck-boost inductance, zero voltage switching (ZVS) can be achieved and thus high efficiency can be obtained. To further improve the efficiency, an adaptive phase-shift control method which determines the phase shift between gating signals according to the load level is also proposced. A low cost digital signal controller dsPIC33FJ16GS502 is adopted in this thesis to realize the power flow control, DC-bus voltage regulation and adaptive phase shift control. As the modulation strategy is a software-based solution, there are no requirement of additional circuits; therefore, it can be easily implemented and reduces instability and noise susceptibility problems. To validate the correctness and the effectiveness of the proposed method, a 300 W prototyping circuit is implemented and tested. According to the experimental results, the measured efficiencies of all operating modes under different loads are all higher than 90%.

碩士<br>崑山科技大學<br>電機工程研究所<br>98<br>In recent years, since the phenomenon of accelerated global warming, the countries have proposed carbon reduction policies and actively seek clean energy. LED lighting devices which to be with saving energy, environmental protection, durable one of the advantages of the device. At present, the prices of general LED lighting products are still expensive. To instead of the conventional lighting apparatus, a simple driver circuit of the LED lighting proposed in this thesis to reduce the price of related products. In this thesis, the driver with Buck-Boost converter would be study. The specifications of LED used which the voltage and current ratings is 3.1~4.3V and 0.7A. The proposed circuit would drive the 3W of 12 series white light LED. The voltage operated in 4V and 0.6A for each LED, to AC 110V rectified by the bridge, then enter the direct current to drive LED of the circuit, And it would be operated with continue mode of Buck-Boost. these results simulated by the Isspice software to be compared. Because of the LED use, only 15% to 25% energy converted into light, various resistance by the temperature, the closed-loop controller of voltage would be used in the circuit proposed. The circuit scheme and operation mode would be done first in this thesis. To make use of the state-space averaging method to export the shortest time required of the stabilizer, and be simulated by the MATLAB required to achieve steady-state controller. Finally, The results showof the LED lighting fixture can achieve a high power factor 1. it is feasible from the experimental results, and is available at the output voltage controlled 48V.

碩士<br>國立雲林科技大學<br>電子工程系<br>102<br>By the development and popularity of portable electronic products, the efficiency enhancement of portable electronic products has become the main trend. Due to the smaller and smaller size of portable electronic products, the application and integration of the power IC chip is more and more important. From the current reference documentary, there is no high-voltage buck-boost converter chip found, and this thesis is the first implement of high-voltage buck-boost converter chip. Firstly, this thesis used the discrete component implemented of high-voltage buck-boost converter, the input supply voltage range is from 16~40V and the output current range is from 0~0.5A; the circuits could all output voltage is 24V. Having the high-voltage buck-boost converter to carry out implement of chips,The propose technique can automatically adjust the on-time value to rapidly increase the inductor current to shorten the transient response time. The system could always maintain steadily the output voltage of 24V within input supply voltage range is 12~40V and output current is 0~1A, and the highest transform efficiency is 86.3%. When the system BUCK is in the operation of 100 mA → 1A with electrical load change, the shortest recovery time could reach 30µs, besides when the BOOST is in the operation of 50mA → 400mA with electrical load variation, the shortest recovery time could reach 31µs. Because the circuits need to use high voltage Power-MOS ,the chip was implemented by TSMC0.25µm HV-COMS HIGH VOLTAGE MIXED SIGNAL, and the size of the circuit layout is 2.18mm2. Additionally , in order to avoid the chip overheat , the high power chip could cause malfunction, therefore , the proposed a low-cost temperature sensor was implemented;, this temperature sensor are truncated four regions: 110 degrees, 130 degrees, 150 degrees, and 170 degrees for circuit detector. the chip was implemented by TSMC0.25µm HV-COMS HIGH VOLTAGE MIXED SIGNAL, and the size of the core layout of the chip is 200µm*141µm. This chip had already submitted to IEEE Sensors Journal was published.

碩士<br>國立雲林科技大學<br>電子工程系<br>104<br>A lot of electronic products require more than one power supply for the system. It will inevitably need a lot of power converter to provide stable voltage and it will occupy a larger silicon area and high power consumption. Therefore, design a high efficient converter with small size is a great challenge。 In this paper, we propose two kinds of converters are using pulse width modulation technology (PWM). One is the single-inductor dual-output (Single-Inductor dual-output, SIDO) buck converter, where the first output voltage is 3.3V and the second output voltage is 2.5V. The PWM frequency operates on 250KHz that can play a maximum output loading current of 1A when the another output is 250mA. The output voltage can be stable at 3.3V and 2.5V in practical tests when the input voltage is 4~5V. The maximum efficiency can reach 94%. The other is single-inductor dual-output (single-inductor dual-output, SIDO) DC - DC buck-boost or boost-boost power converter. For buck-boost converter, the first is the boost output, where the output voltage is 6V; the second is buck converter, where the output voltage is 3.3V. The PWM frequency operates at the 125KHz, which the maximum output loading current is about 150mA.When he input voltage is 5.3V, the output loading current supports 66mA and 100mA for 6V and 3.3V respectively. The highest efficiency can reach 89%. Two converters using the same inductor, which can save chip area and reduce power dissipation, when compared to the traditional converter.

碩士<br>明新科技大學<br>電機工程研究所<br>96<br>In this thesis, an adaptive digital control scheme is proposed for the buck-boost converter using the desired pole/zero assignment approach. The controller design is based on the small signal model of the buck-boost converter and the sensitivity function to meet the internal stability requirement. The control design of the buck-boost converter is a challenging work because the system, which is a non-minimum phase (NMP) system, has a right half-plane zero. In the case that the plant parameters are well known, through the sensitivity function a digital controller for the buck-boost converter with desired pole/zero assignment is proposed to meet the requirements of internal stability for the closed-loop system. In the case that the plant parameters are uncertain (or unknown), through the sensitivity function a digital adaptive controller for buck-boost converter with desired pole/zero assignment is also proposed using the recursive least-squares (RLS) algorithm to satisfy the requirement of internal stability for the closed-loop system. A projection algorithm is also proposed for the estimated parameters to satisfy the characteristics of poles and zero where poles should be inside the unit circle and zero should be outside the unit circle, respectively. To verify the validity of the proposed digital controller for the buck-boost converter, numerical simulations are performed using Matlab. Form these simulations, the estimated parameters can approach their actual values of the plant parameters using the recursive least-squares algorithm and the output voltage can be regulated by the proposed adaptive digital controller. Finally, experimental set-up is built for the buck-boost converter and the fully digital adaptive controller is implemented by a digital signal processor TMDXEZ28335. From the experimental results, the proposed adaptive digital controller has sound performance for the buck-boost converter. The proposed method is simple and is suitable for practical control design for the buck-boost converter.

碩士<br>淡江大學<br>航空太空工程學系碩士班<br>100<br>This thesis presents the design of a programmable non-inverting synchronous buck-boost dc-dc power converter. The system contains two major subsystems, namely, a synchronous buck-boost power converter and a control unit. The buck-boost converter is capable of converting the source supply voltage to higher and lower voltages to the load terminal with voltage polarity unchanged. The voltage regulation is achieved through the control of a specially designed feedback circuit using a light dependent resistor from the control unit. A feedback control system to ensure the performance of the power converter is established. The hardware/software integrated and function tested prototype system is built in the laboratory. The system is successfully utilized for the maximum point tracking for the solar power management system using natural sunlight as the irradiance source. The system can be tailored to other power control applications through minor modification to the software of the control unit.

碩士<br>元智大學<br>電機工程學系<br>99<br>The design and implementation of a Signal-Inductor-Double-Output(SIDO) switching buck-boost DC-DC converter is presented. The system operates in pseudo-continuous conduction mode(PCCM). By adaptively controlling the duty intervals for inductor charging, buck conversion, boost conversion, and freewheeling respectively, the system manages the dynamic inductor current level to achieve stable output voltages and high efficiency. The DC-DC converter was implemented in TSMC 0.35-μm 2P4M CMOS process with die size of 1.18×1.16 mm2. According to measurement results, the maximum peak-to peak output voltage ripple less than 90mV and current ranges between 50mA and 500mA. The DC-DC converter operates in frequency 350kHz and supply voltage ranges from 2 to 2.4V. The output voltage is 1.2V and 2.4V.

In the fast growing field of Telecommunications, the back up DC power supply plays a vital role in powering the telecom equipment. This DC power supply is a combination of AC-DC Rectifier coupled with a battery bank to support the load when AC input is not available. Figures 0.1 and 0.2 show the line diagram of the DC power supply. The power supply is the most critical element in a telecom installation and it should be highly reliable in order to have un-interrupted service. (Fig) Besides reliability, power density and cost are the driving forces behind the success of a power supply in the market. Off late, the reach of telecom in the society is very wide covering remote villages and major metros. Given this environment, the power supply is exposed to extreme input conditions. It is desirable to design the power supply capable of withstanding wide AC input conditions. Another advantage is that the rectifier unit will keep the battery charged so that the battery will have long life. This thesis is aimed at designing a 1400W (56V/25A) telecom power supply, keeping in view of the issues expressed above. The aim is to design a Switched Mode Rectifier (SMR) that tolerate wide input voltage variations (90Vac to 300Vac). In addition, the design covers unity input power factor, high efficiency (> 90%), high power density ( ), parallel operation and low cost ( ). Chapter 1 of this thesis covers the context and motivation of the work. Chapter 2 presents the design issues pertaining to power supplies. The normalized description of the power converters is presented. Such a description enables one to compare several circuit topologies in order to make effective design decisions. In a similar way the effectiveness of the switches and mgnetics are presented to enable design decisions in the output stage of the rectifier. Chapter 3 presents the design of the 1400W telecom power supply, keeping in view of the stated specifications. The performance results of the converter are presented in Chapter 4. All the design goals have been met. The design exercise has also given insights into possible further improvements. Contributions from this work and course of future development work are indicated in the concluding chapter.

In the fast growing field of Telecommunications, the back up DC power supply plays a vital role in powering the telecom equipment. This DC power supply is a combination of AC-DC Rectifier coupled with a battery bank to support the load when AC input is not available. Figures 0.1 and 0.2 show the line diagram of the DC power supply. The power supply is the most critical element in a telecom installation and it should be highly reliable in order to have un-interrupted service. (Fig) Besides reliability, power density and cost are the driving forces behind the success of a power supply in the market. Off late, the reach of telecom in the society is very wide covering remote villages and major metros. Given this environment, the power supply is exposed to extreme input conditions. It is desirable to design the power supply capable of withstanding wide AC input conditions. Another advantage is that the rectifier unit will keep the battery charged so that the battery will have long life. This thesis is aimed at designing a 1400W (56V/25A) telecom power supply, keeping in view of the issues expressed above. The aim is to design a Switched Mode Rectifier (SMR) that tolerate wide input voltage variations (90Vac to 300Vac). In addition, the design covers unity input power factor, high efficiency (> 90%), high power density ( ), parallel operation and low cost ( ). Chapter 1 of this thesis covers the context and motivation of the work. Chapter 2 presents the design issues pertaining to power supplies. The normalized description of the power converters is presented. Such a description enables one to compare several circuit topologies in order to make effective design decisions. In a similar way the effectiveness of the switches and mgnetics are presented to enable design decisions in the output stage of the rectifier. Chapter 3 presents the design of the 1400W telecom power supply, keeping in view of the stated specifications. The performance results of the converter are presented in Chapter 4. All the design goals have been met. The design exercise has also given insights into possible further improvements. Contributions from this work and course of future development work are indicated in the concluding chapter.

碩士<br>龍華科技大學<br>電子系碩士班<br>93<br>Abstract The design and implementation of a DC-DC switching converter for low supply voltage electronic system is presented in this thesis.This switching converter has low output ripple in steady state and fast transient response when the load is suddenly changed. It also has high power conversion efficiency that is suitable for portable electronic applications that are powered by batteries such as mobile phone, digital camera, PDA, etc. The control circuit of the switching converter proposed in this thesis is to adopt the structure of the hysteresis current control method, there can be better line regulation. The main principle is to apply the mechanism of feedback-loop theory and fix the output voltage at the desired value without concerning the load current. We need to use voltage and current feedback to control it. The current feedback, by sensing signal is usually obtained an accurate resistor to inductor. The method, however, decreases the convert efficiency. To improve the above deficiency, we proposed the current-sensing circuit to measure current. Meanwhile, MOS will be used to replace flywheel diode on converter to enhance power efficiency. The power efficiency could be up to 90 %. Therefore, it is suitable for the porfable application. The converter consists to the error amplifier, hysteresis current comparator circuit, sample and hold circuit, nonoverlapping circuit, current sensing circuit and driver circuit. The chip is implemented with TSMC 0.35μm 2P4M CMOS processes. The detailed performances will be described in the following chapters.

碩士<br>中原大學<br>電機工程研究所<br>98<br>In this thesis, the design of a novel topology of bidirectional buck-boost DC/DC converter for photovoltaic module is the study objective. The system architecture includes solar cells, novel topology of bidirectional buck-boost DC/DC converter, lead-acid battery and a single-chip microcontroller (PIC). Due to high degree global industrialization, environmental pollution and energy shortages are becoming serious problems in nowadays, therefore it is imperative to develop renewable energy. In a variety of renewable energies, solar energy is one of the most attractive selections. Converters are absolute necessity for solar power applications. This thesis presents a novel topology of bidirectional buck-boost DC/DC converter which can manage and control both of charging and discharging functions for using in a solar cells system. Finally, through simulation and experimental measurement, this design has been verified.

碩士<br>逢甲大學<br>綠色能源科技碩士學位學程<br>103<br>This paper describes the application of a back electromotive force (BEMF) with DC brushless motor drives. Digital Signal Processor (DSP) as a core controller. DSP is performed by switching function mode. To improve the efficiency BEMF with motor recovered to the battery, By converting electrical energy into the battery to the motor, Using Bi-direction buck / boost converter to step-down power supply to drive the motor voltage, when BEMF is activate the recovered energy to charge the battery, if BEMF voltage is over it will buck charging, on the other hand, the BEMF is too small, it will boost charging, thus achieving the two-way conversion function and enhance endurance battery capacity use. In order to achieve accurate Pulse Width Modulation (PWM) output signal, the system architecture uses two dsPIC DSP controller to the drive motor inverter circuit and bi-directional buck / boost converter. Hall device is the sensing signals control it interior of the motor sensor, for each mode switch for instant correction. When gliding or braking BEMF will generated, the BEMF energy will assertion, by accessibility the charge voltage converter. The results of the experiment is accomplish use bi-direction buck / boost circuit to achieve the purpose of energy recovery.

碩士<br>國立臺北科技大學<br>電腦與通訊研究所<br>100<br>The first part of this thesis is a flying-capacitor buck-boost converter with wide output range has been proposed to improve efficiency of conventional switched-capacitor converter. The proposed converter has the properties of fast response and the non-pulsating output current, which can reduce both of output voltage ripple and current stress requirement of the output capacitor. The proposed structure utilized pulse-width-modulation technique. The proposed converter can supply an output voltage with wide range which is from 1.0V to 4.5V in high accuracy when supply voltage is 3.3V. The max switching frequency of the proposed converter is 1 MHz. Experimental results proved that the proposed scheme improves the power efficiency up to 90%. The proposed buck-boost converter has been fabricated with TSMC 0.35-μm CMOS 2P4M process, the total chip area is 2.308 × 2.24 mm2 (with PADs). The second part of this thesis introduces the design of fast transient response flying-capacitor buck-boost converter with wide output range utilizing pseudo-current mode techniques. The proposed structure utilized pseudo-current mode technique to achieve fast transient response when load current changes between heavy load and light load. The switching frequency of the proposed buck-boost converter is 1 MHz for supply voltage is 3.3V and output range is from 1.0V to 4.5V. Experimental results prove that the proposed scheme improves the transient response is within 2 μs and the power efficiency up to 89.66%. The proposed buck-boost converter has been fabricated with TSMC 0.35-μm CMOS 2P4M process, the total chip area is about 1.5 × 1.5 mm2 (with PADs).

碩士<br>國立臺北科技大學<br>電子工程系<br>106<br>This thesis proposes a low-EMI delta-sigma modulation buck converter and a low voltage adaptive on-time controlled boost converter. The first converter is proposed to improve the drawback of the conventional PWM converter. This converter mainly utilizes the noise-shaping and oversampling theories to spread the harmonic tones in the output spectrum. The proposed delta-sigma buck converter has been fabricated with TSMC 0.35-μm 2P4M CMOS process. The output range is 1V-2.8V and input range is 3V-3.6V. When the output load range changes from 50mA to 500mA and from 500mA to 50mA, the time of transient response is 4μs and 4μs, respectively. The chip area is 1.32×1.38 mm2. The second converter is a boost converter, which is for the output of the solar battery. It will convert the lower voltage of the cell to the appropriate level for the portable product and lithium battery. It proposes the current ripple sensing and zero current detector (ZCD) circuit to improve the efficiency in the light load. The proposed boost converter has been fabricated with TSMC 0.18-μm 1P6M CMOS process. The output voltage is designed at 1.8V and the input range is from 0.5V to 1.2V. When the load current steps are from 1mA to 200mA and from 200mA to 1mA, the time of the transient response is 2μs and 1.5μs, respectively. The total chip area is 1.15×1.17 mm2.

碩士<br>輔仁大學<br>電機工程學系碩士班<br>102<br>Design and implementation of fuzzy sliding-mode controlled multiphase DC-DC buck/boost converter with coupled inductor which proposed in this dissertation. This is the extension of interleave control, coupled inductor and soft switching technology that lead into the basic buck/boost converter. The proposed converter structures contribute increase output power, reduce current ripple, switching loss, and converter volume. The article discusses the analysis of equivalent inductance and inductor current at different conduction modes, through fuzzy sliding mode control get a more accurate and stable output voltage. Furthermore, it can be applied in a PV storage system on the lithium battery for charging and discharging. Simulation and experimental results show the feasibility and correctness of the proposed converter and control system.

碩士<br>輔仁大學<br>電機工程學系碩士班<br>101<br>Lithium-ion batteries for its superior performance, have been widely used nowadays, such as Electric Vehicle （EV）, Hybrid Electric Vehicle （HEV）, Communication energy systems, portable products, etc. However, In order to fulfill the power consumption of requirements, battery cells would connect in parallel or series. This thesis presents a bidirectional buck-boost converter with energy transfer capacitor based battery equalization scheme with state of charge（SOC） estimation. The architecture ensured the batteries operated within safety limits, estimated the open circuit voltage（OCV） of each unit cell accurately, and achieved SOC balancing between battery cells during charge/discharge.

碩士<br>國立交通大學<br>電控工程研究所<br>106<br>Nowadays, solar energy has become increasingly important because it is a form of renewable energy and possessed of several advantages, such as simple implementation, environmental cleanness, low maintenance cost and inexhaustible nature. However, there also exist some disadvantages, for example, low conversion efficiency, variable irradiance condition and daylight limitation. To overcome the demerit of low efficiency, MPPT control is usually required in a standalone PV system to extract the maximum power from a solar module. A standalone photovoltaic system is built up in this thesis by a solar module, a DC-DC converter, a D.C. fan and a battery as payloads. Consider to the payloads which require a positive voltage, this thesis implements the MPPT control with a non-inverting buck-boost converter to generate a positive output. To improve the effect caused by variable irradiance condition and daylight limitation, this thesis further proposed the power management strategy combined with an improved MPPT control based on incremental conductance method to deliver the power to the payloads efficiently. The improvement of the proposed system has been verified through simulation and experiment results.

碩士<br>明新科技大學<br>電機工程研究所<br>96<br>In this thesis, a model reference adaptive digital control scheme is proposed for the buck-boost converter. The controller design is based on the small signal model of the buck-boost converter and a reference model. The control design of the buck-boost converter is a challenging work because the system, which is a non-minimum phase (NMP) system, has a right half-plane zero. A cost function of the output error (i.e. the difference between the reference model output and the plant output) and weighting control input is minimized for the buck-boost converter using the model reference adaptive control scheme, without the assumption that the unstable plant zero must be the zero of the reference model. In the case that the plant parameters are well known,a digital controller is obtained for the buck-boost converter by solving a Diophantine equation. In the case that the plant parameters are uncertain (or unknown), a digital controller with model reference adaptive control scheme is proposed for the buck-boost converter using the recursive least-squares (RLS) algorithm where the cost function of the output error and weighting control input is also minimized. To verify the validity of the proposed digital controller for the buck-boost converter, numerical simulations are performed using MATLAB. Form these simulations, the estimated parameters can approach their actual values of the plant parameters using the recursive least-squares algorithm and the output voltage can be regulated by the proposed adaptive digital controller. Finally, experimental set-up is built for the buck-boost converter and the fully digital adaptive controller is implemented by a digital signal processor TMS320-F28335. The proposed method is simple and is suitable for practical control design for the buck-boost converter.

碩士<br>國立勤益科技大學<br>電子工程系<br>105<br>DC-DC conversion would provide the correct power to the system needed. Many different varieties of voltage regulators with a variety of control schemes are used. DC-DC converters are some of the most widely used power electronics circuits for its conversion efficiency and flexible output voltage. In this thesis 3 common topologies that makes useful are the Buck, Boost, and the Buck Boost converters. These converters used for electronic devices are designed to regulate the output voltage against the changes of the input voltage and load current. The first converter is a buck converter which steps a voltage down. The producing voltages would be lower than the input voltage. The next converter is a boost converter that steps a voltage up producing a voltage higher than the input voltage. A buck boost converter step a voltage up or down, producing a voltage equal to or higher or lower than the input voltage. The performance has been proved by the Multisim software. The performance simulation mainly focuses on analysis of different DC-DC converters. Each converter has its own peak-to-peak inductor ripple current, peak-to-peak capacitor, inductor, on switch of different converters, all of which are expressed mathematically.