Tesi sul tema "Direct Current Converter (DC/DC)"
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Gowaid, Islam Azmy. "DC-DC converter designs for medium and high voltage direct current systems". Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=27933.
Luth, Thomas. "DC/DC converters for high voltage direct current transmission". Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/24466.
Jimenez, Carrizosa Miguel. "Hierarchical control scheme for multi-terminal high voltage direct current power networks". Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112039/document.
This thesis focuses on the hierarchical control for a multi-terminal high voltage direct current (MT-HVDC) grid suitable for the integration of large scale renewable energy sources. The proposed control scheme is composed of 4 layers, from the low local control at the power converters in the time scale of units of ms; through distributed droop control (primary control) applied in several terminals in the scale of unit of seconds; and then to communication based Model Predictive Control (MPC) that assures the load flow and the steady state voltage/power plan for the whole system, manage large scale storage and include weather forecast (secondary control); finally reaching the higher level controller that is mostly based on optimization techniques, where economic aspects are considered in the same time as longer timespan weather forecast (tertiary control).Concerning the converters' level, special emphasis is placed on DC/DC bidirectional converters. In this thesis, three different topologies are studied in depth: two phases dual active bridge (DAB), the three phases DAB, and the use of the Modular Multilevel Converter (MMC) technology as DC/DC converter. For each topology a specific non-linear control is presented and discussed. In addition, the DC/DC converter can provide other important services as its use as a direct current circuit breaker (DC-CB). Several operation strategies are studied for these topologies used as DC-CB.With respect to primary control, which is the responsible to maintain the DC voltage control of the grid, we have studied several control philosophies: master/slave, voltage margin control and droop control. Finally we have chosen to use droop control, among other reasons, because the communication between nodes is not required. Relative to the secondary control, its main goal is to schedule power transfer between the network nodes providing voltage and power references to local and primary controllers, providing steady state response to disturbances and managing power reserves. In this part we have proposed a new approach to solve the power flow problem (non-linear equations) based on the contraction mapping theorem, which gives the possibility to use more than one bus for the power balance (slack bus) instead of the classic approach based on the Newton-Raphson method. Secondary control plays a very important role in practical applications, in particular when including time varying power sources, as renewable ones. In such cases, it is interesting to consider storage devices in order to improve the stability and the efficiency of the whole system. Due to the sample time of secondary control is on the order of minutes, it is also possible to consider different kinds of forecast (weather, load,..) and to achieve additional control objectives, based on managing storage reserves. All these characteristics encourage the use of a model predictive control (MPC) approach to design this task. In this context, several possibilities of optimization objective were considered, like to minimize transmission losses or to avoid power network congestions.The main task of tertiary control is to manage the load flow of the whole HVDC grid in order to achieve economical optimization. This control level provides power references to the secondary controller. In this thesis we were able to maximize the economic profit of the system by acting on the spot market, and by optimizing the use of storage devices. In this level it is again used the MPC approach.With the aim of implementing the hierarchical control philosophy explained in this thesis, we have built an experimental test bench. This platform has 4 terminals interconnected via a DC grid, and connected to the main AC grid through VSC power converters. This DC grid can work at a maximum of 400 V, and with a maximum allowed current of 15 A
Toussaint, Pierre. "De la quasi-resonance introduite dans les convertisseurs, DC-DC de moyenne puissance : application à l'absorption sinusoïdale". Cachan, Ecole normale supérieure, 1994. http://www.theses.fr/1994DENS0013.
Steckler, Pierre-Baptiste. "Contribution à la conversion AC/DC en Haute Tension". Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI075.
As Alternating Current (AC) is well suited for most of the production, transmission, and distribution applications, its massive use is easy to understand. However, for over a century, the benefits of High Voltage Direct Current (HVDC) for long-distance energy transmission are well known. To connect both, AC/DC converters are mandatory, whose nature evolves with technological progress. After the problematic induced by HVDC on AC/DC converters is presented, this manuscript is focused on three topologies: Modular Multilevel Converter (MMC), Alternate Arm Converter (AAC) and Series Bridge Converter (SBC). They are presented, sized, analyzed thoroughly, and compared in quantitative terms, using original key performance indicators. It appears that MMC and SBC are particularly promising. The conventional control method of the MMC is then presented, and its structural properties are highlighted. A first original control law is presented, with similar performances but less complexity than the state-of-the-art. A second control law, non-linear and based on differential flatness theory, is introduced. It allows a very fast power tracking response while ensuring the global exponential stability of the system. These control laws are tested in simulation, using an average model and a detailed model with 180 sub-modules per arm. The last part is dedicated to the SBC. After a modeling step, some results regarding its structural analysis are presented, and an original control law is introduced. The essential role of the transformer for series converters like the SBC is highlighted. Finally, the performance of the proposed control law is assessed in simulation
Yang, Gang. "Design of a High Efficiency High Power Density DC/DC Converter for Low Voltage Power Supply in Electric and Hybrid Vehicles". Thesis, Supélec, 2014. http://www.theses.fr/2014SUPL0011/document.
In this dissertation, a 2.5kW 400V/14V, 250kHz DC/DC converter prototype is developed targeted for electric vehicle/hybrid vehicle applications. Benefiting from numerous advantages brought by LLC resonant topology, this converter is able to perform high efficiency, high power density and low EMI. A first part of this dissertation is the theoretical analysis of LLC: topology analysis, electrical parameter calculation and control strategy. To arrange high output current, this thesis proposes parallel connected LLC structure with developed novel double loop control to realize an equal current distribution. The second part concerns on the system amelioration and efficiency improvement of developed LLC. A special transformer is dimensioned to integrate all magnetic components, and various types of power losses are quantified based on different realization modes and winding geometries to improve its efficiency. This converter also implements a robust synchronous rectification system with phase compensation, a power semiconductor module, and an air-cooling system. The power conversion performance of this prototype is presented and the developed prototype has a peak efficiency of 95% and efficiency is higher than 94% from 500W to 2kW, with a power density of 1W/cm3. The CEM analysis of this converter is also developed in this thesis
Verdicchio, Andrea. "Nouvelle électrification en courant continu moyenne tension pour réseau ferroviaire". Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0093.
Since the beginning of the 20th century, various DC and AC rail electrification systems have beendeveloped in Europe. Single-phase, medium-voltage AC systems (25 kV-50 Hz or 15 kV 16.7 Hz)allow the use of a light overhead-line of small copper cross-section but by their principle involvefluctuating power and reactive power that have to be compensated by large and expensivedevices. DC electrification systems (1.5kV or 3kV) do not have these disadvantages but in return,their relatively low voltage level involves the circulation of high currents in the overhead-line whichlimits any increase in traffic because the copper section cannot be increased beyond 1000 mm2.From a rolling stock point of view, AC powered locomotives have a complex and voluminousconversion chain (step-down transformer, rectifier, low-frequency filter and traction inverter). Onthe other hand, a conversion chain operating under direct current catenary is reduced to an inputfilter and a traction inverter. Today, the technological progress made in the field of powerelectronics makes it possible to envisage the development of medium voltage DC grids to supportthe energy transition by integrating more easily renewable energy sources and storage devices.On the basis of this observation, the aim of this thesis is to propose a new medium voltage DCrailway electrification system, on the one hand, with the aim of combining the advantages of thecurrent railway electrification systems and on the other hand, to consider in the medium term therenovation of lines electrified in DC. The first chapter of this thesis presents a state of the art ofexisting railway electrification systems and associated traction chains. The second chapterhighlights the interest of a medium voltage DC electrification for railway traction. A calculationmethod for determining the DC voltage level for a given traffic is proposed. Therefore, it is shownthat the choice of a voltage level at 9 kV makes it possible to obtain an overhead-line cross-section and a substation spacing comparable to the 25 kV-50 Hz system. In its first part, the thirdchapter proposes a strategy to upgrade the existing 1.5 kV French electrification system to a 9 kVsystem. Until the fleet of traction units is adapted to operate at 9 kV, it is possible to prepare theevolution of the electrification system by deploying a transmission line at 9 kV (feed-wire) inparallel with the existing 1.5 kV overhead-line. At the end of the transition period, the 1.5 kVvoltage level is completely removed and the entire infrastructure as well as the traction unitsoperate at 9 kV. The second part of this chapter is dedicated to the study of a topology, based onan association of isolated DC/DC converters, to fulfil the function of solid state transformer whichis essential for the power reinforcement of the 1.5 kV system from the 9 kV feed-wire. The fourthchapter presents the realization and tests of an isolated DC / DC converter with a power level of300 kW using 3.3 kV SiC MOSFET modules. A general conclusion and perspectives conclude thismanuscript
Vidales, Luna Benjamin. "Architecture de convertisseur intégrant une détection de défauts d'arcs électriques appliquée au sources d'énergie continues d'origine photovoltaïques". Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0040.
In this research work, the development of a multilevel inverter for PV applications is presented. The PV inverter, has two stages one DC/DC converter and one DC/AC inverter, and is capable of generating an AC multilevel output of nine levels, it's a transformerless inverter and uses a reduced number of components compared to other topologies. The conception of a novel DC/DC converter is capable of generating two isolated DC voltage levels needed to feed the DC/AC stage. This DC/DC stage is developed in two variants, buck and boost, the _rst to perform the reduction of voltage when the DC bus is too high, and second to increase the voltage when the DC bus is too low to perform interconnection with the grid through the DC/AC inverter. This is achieved thanks to the parallel functioning of the developed topology, which make use of moderated duty cycles, that reduces the stress in the passive and switching components, reducing potential losses. The validation of the PV inverter is performed in simulation and experimental scenarios. In the other hand, the response of the inverter facing an arc fault in the DC bus is studied by performing a series of tests where the fault is generated in strategic points of the DC side, this is possible thanks to the design and construction of an arc fault generator based in the specifications of the UL1699B norm. During the tests is observed that with the apparition of an arc fault, there is a lost in the half-wave symmetry of the AC multilevel output voltage waveform, generating even harmonics which aren't present during normal operation, only when an arc fault is present in the DC system. The monitoring of even harmonics set the direction for developing the detection technique. Since the magnitude of even harmonics in the inverter is very low, the total even harmonic distortion is employed as a base for the detection technique presented in this thesis. The effectiveness of this method is verified with a series of tests performed with different loads
Hadjikypris, Melios. "Supervisory control scheme for FACTS and HVDC based damping of inter-area power oscillations in hybrid AC-DC power systems". Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/supervisory-control-scheme-for-facts-and-hvdc-based-damping-of-interarea-power-oscillations-in-hybrid-acdc-power-systems(cc03b44a-97f9-44ec-839f-5dcbcf2801f1).html.
Mai, Yuan Yen. "Current-mode DC-DC buck converter with current-voltage feedforward control /". View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?ECED%202006%20MAI.
Bandyopadhyay, Saurav. "45nm direct battery DC-DC converter for mobile applications". Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/60149.
Includes bibliographical references (p. 65-66).
Portable devices use Lithium-ion batteries as the energy source due to their high energy density, long cycle life and low memory effects. With the aggressive downscaling of CMOS, it is becoming increasingly difficult to efficiently interface the low voltage, low power digital baseband and DSP of the mobile phone with the battery which maybe at voltages as high as 4.2V. This is efficiently done by a DC-DC converter which is a separate IC designed on an older generation process capable of handling high voltages. However, this requires an extra IC, thereby increasing the overall system cost. Here, a buck converter is demonstrated on a standard 45nm digital CMOS process which can be integrated with the 45nm digital core on the same die. This converter is capable of handling high battery voltages (2.8V to 4.2V) and delivers a regulated low voltage (0.5V to 1.1V) to the digital core. The converter can supply 20[mu]A to 100mA of load current. The peak efficiency of the converter is 87% for 73mW output at 4.2V supply and for the ultra low power levels, efficiency of 75% is obtained for a 20[mu]W load at 3V. Both pulse width modulation (PWM) and pulse frequency modulation (PFM) modes of control are used. A new digital pulse width modulator (DPWM) architecture is presented which provides 75% area savings over the conventional delay line and counter based architecture with comparable power consumption. The buck converter also requires Switched Capacitor (SC) DC-DC Converters to generate stacking regulators and regulator for the control circuitry. On the whole, the complete system integrates the Power Management Unit with the core for a single chip radio in 45nm.
by Saurav Bandyopadhyay.
S.M.
Chen, Christine M. Eng Massachusetts Institute of Technology. "Integrated DC-DC converter with ultra-low quiescent current". Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/84879.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 93-94).
Based on the LTC3588, the design of a bandgap reference and a comparator for use in the control circuitry of DC-DC converter with an ultra-low quiescent current of 150nA is presented here. Not only will this thesis discuss the challenges encountered over the course of designing circuits to operate at such low current levels, but it will also provide proof of concept silicon evaluation data of modified LTC3588 chips demonstrating that such low current operation is viable.
by Christine Chen.
M.Eng.
Khopkar, Rahul Vijaykumar. "DC-DC converter current source fed naturally commutated brushless DC motor drive". Texas A&M University, 2003. http://hdl.handle.net/1969.1/1257.
Fan, Shixiong. "Current source DC/DC converter based multi-terminal DC wind energy conversion system". Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=17007.
Lau, Wai Keung. "Current-mode DC-DC buck converter with dynamic zero compensation /". View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?ECED%202006%20LAU.
zhou, hua. "MAGNETICS DESIGN FOR HIGH CURRENT LOW VOLTAGE DC/DC CONVERTER". Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3381.
Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering PhD
Prasantanakorn, Chanwit. "Current Sharing Method for DC-DC Transformers". Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/31112.
Master of Science
Van, Rhyn P. D. "High voltage DC-DC converter using a series stacked topology". Thesis, Link to the online version, 2006. http://hdl.handle.net/10019/1269.
Choi, Byungcho. "Large signal transient analysis of duty ratio controlled DC-to-DC converter". Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43966.
Master of Science
Saini, Dalvir K. "True-Average Current-Mode Control of DC-DC Power Converters: Analysis, Design, andCharacterization". Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1531776568809249.
Zhang, Lu. "Development of LCL DC/DC transformer and fault current limiting LCL VSC converter for high power DC networks". Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=211240.
Baglan, Fuat Onur. "Design Of An Educational Purpose Multifunctional Dc/dc Converter Board". Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12610103/index.pdf.
Bills, David Marlin. "Soft Switching Multi-Resonant Forward Converter DC to DC Application for Communications Equipment". Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3497.
M.S.E.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering MSEE
Smith, Nathaniel R. "Characterization and Design of Voltage-Mode Controlled Full-Bridge DC/DC Converter with Current Limit". Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright152721348332911.
Witts, Joseph Harris James G. "Cal Poly SuPER system photovoltaic array universal DC-DC step down converter : a thesis /". [San Luis Obispo, Calif. : California Polytechnic State University], 2008. http://digitalcommons.calpoly.edu/theses/2/.
"June 2008." "In partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering." "Presented to the faculty of California Polytechnic State University, San Luis Obispo." Major professor: James Harris, Ph.D. Includes bibliographical references (leaves 70-72). Also available online and on microfiche (2 sheets).
Thekkevalappil, Soniya Noormuhamed. "Hysteretic pulse width modulation with internally generated carrier for a boost dc-dc converter". [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0013267.
Deepak, G. "Integrated Magnetics Based DC-DC Converter Topologies For A DC Micro-Grid". Thesis, 2012. https://etd.iisc.ac.in/handle/2005/2310.
Deepak, G. "Integrated Magnetics Based DC-DC Converter Topologies For A DC Micro-Grid". Thesis, 2012. http://etd.iisc.ernet.in/handle/2005/2310.
Lakshminarasamma, N. "A New Family Of Soft Transition DC-DC Converters". Thesis, 2007. https://etd.iisc.ac.in/handle/2005/613.
Lakshminarasamma, N. "A New Family Of Soft Transition DC-DC Converters". Thesis, 2007. http://hdl.handle.net/2005/613.
Swaminathan, B. "Resonant Transition Topologies For Push-Pull And Half-Bridge DC-DC Converters". Thesis, 2004. https://etd.iisc.ac.in/handle/2005/317.
Swaminathan, B. "Resonant Transition Topologies For Push-Pull And Half-Bridge DC-DC Converters". Thesis, 2004. http://hdl.handle.net/2005/317.
Γιαννόπουλος, Σπυρίδων. "Έλεγχος τριφασικού ac/dc αντιστροφέα από την πλευρά του δικτύου για απευθείας στήριξη της αέργου ισχύος με τοπική παραγωγή αιολικού συστήματος". Thesis, 2014. http://hdl.handle.net/10889/8095.
The continuously increasing energy requirements of modern society combined with the rapid climate changes lead us to the need to produce electrical energy in a more economic and environmentally friendly way. Thus, the Renewable Energy Sources gain an increasing share of electrical energy production, constantly changing the global energy map. Wind power systems, which utilize the kinetic energy of the wind, are a kind of RES. In this thesis we study a wind power system, which comprises a variable speed wind turbine, which uses a permanent magnet synchronous machine, a voltage source converter, an R-L filter in the grid side and a short transmission line. The increased reliability and performance of PMSG make it particularly attractive solution for wind power systems. In this thesis we simulate in Matlab/Simulink environment the system described above. Applying appropriate control techniques on the machine side we try to achieve maximum power harvesting from the wind, while on the grid side we try through direct power flow control to achieve unit power factor with simultaneous control of the dc link voltage. Then, using an additional control we try to keep constant the voltage at the end of the R-L filter during a grid voltage drop. Finally, we present the simulation results along with a brief commentary and the conclusions.
劉育廷. "Digital Current Mode DC-DC Converter". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/91935440386309142214.
Shyam, V. "Development Of An Application Specific Parallel Processing Real-Time System For MTDC System Control". Thesis, 1996. https://etd.iisc.ac.in/handle/2005/1755.
Shyam, V. "Development Of An Application Specific Parallel Processing Real-Time System For MTDC System Control". Thesis, 1996. http://etd.iisc.ernet.in/handle/2005/1755.
Yu-Hui, Sung, e 宋玉惠. "Implementation of 8MHz Current-Mode Buck DC-DC Converter". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/17297645957351678156.
國立交通大學
電機學院IC設計產業專班
95
This thesis proposes a new DC-DC switching converter with a high switching frequency for reducing the size of the output filter. Owing to the high switching frequency, the on-chip output filter in DC-DC switching converter is possible in the future. Thus, how to develop a DC-DC switching converter with high switching frequency is important in today’s technology. Therefore, a compact solution is needed to effectively reduce the footprint area of the power management module in system-on-chip (SoC) systems. Furthermore, a high performance power converter module is also needed to provide a regulated and stable supply voltage to the SoC systems because the operation voltage of the SoC systems is too low to have a good signal-to-noise ratio. For providing a high performance supply voltage, the current-mode technique is utilized to get better line and load regulations. However, the current sensing accuracy and response time is seriously affected by the high switching frequency. A high accuracy and small response time current sensor is also proposed in this thesis. In thesis, we implement an 8 MHz current-mode buck DC-DC converter with good line and load regulations. The chip is implemented by tsmc 2P4M 0.35u CMOS process. The range of the operation voltage is from 2.6V to 3.3V. The load regulation and line regulation are 0.88uV/mA and 4.67mV/V. The chip features smaller output filter elements and fast response, which makes it suitable for power management in the portable devices.
Chen, Chien-cheng, e 陳建成. "A High Efficiency Current Mode Control DC-DC Buck Converter". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/07494232505610402844.
國立中央大學
電機工程研究所
99
In this changing rapidly era of electronic technology, the major demands of portable electronics are short, thin, and full functionalities. These sub-circuits of the portable electronics, which use batteries for power sources, need a stable supply voltage generating by power converters. These power converters must have low power consumption and high efficiency to extend the service time of portable electronics. Thus, a high efficiency current mode buck converter is presented in this thesis. The proposed buck converter uses current-mode controlling mechanism to accelerate the transient response during the transient period. It senses the current variation of the output inductor. Therefore, it achieves low operating current and high efficiency by removing the V-to-I converting circuit. This buck converter has better performance in the specification of efficiency comparing with traditional buck converter with current-mode controlling. This current-mode buck converter is fabricated with TSMC 0.35um 3.3 V CMOS process. In the proposed buck converter, the operation voltage is form 3.8 V to 5.5 V, the output voltage is 3.3 V, the output current is from 0.05 A to 1 A, and the highest efficiency is 97.4 %. The line regulation and load regulation are 17.5 mV/V and 1.15 mV/A, respectively. The chip area is 2.46 mm2.
Chin-HongChen e 陳津宏. "Average-Current-Mode Non-inverting Buck-Boost DC-DC Converter". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/77890091296649204660.
國立成功大學
電機工程學系碩博士班
98
With the increasing use of electrical portable devices, an efficient power management solution is needed to extend battery life. Generally, basic switching regulators (e.g., buck, boost) are not capable of using the entire battery output characteristics effectively (e.g., 2.7–4.2 V for Li-ion) to provide a fixed output voltage (e.g., 3.3V). In this work, an average-current-mode non-inverting buck-boost dc-dc converter is introduced, which can use the full-range output voltage of Li-ion battery with the advantages of high power efficiency, faster transient response, and excellent noise immunity. The die area of this chip is 1.9x1.7 , which is fabricated by using Taiwan Semiconductor Manufacturing Company (TSMC) 0.35μm 2P4M 5V mixed-signal polycide process. The converter output is set to 3.3V, and can supply up to 300 mA load current. Its input votlage can range from 2.5V to 5V.
Chen, Chien-Nan, e 陳建男. "A Current-Mode CMOS DC-DC Switching Converter with on-chip Current-Sensor". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/85539169363340614963.
國立臺灣科技大學
電子工程系
95
A current-mode CMOS DC–DC converter with integrated power switches and on-chip current sensor for feedback control is presented in this paper. The sensed inductor current, combined with the internal ramp signal, can be used for current-mode DC–DC converter feedback control. In addition, no external components and no extra I/O pins are required for the current-mode controller. The DC–DC converter has been fabricated with the TSMC CMOS digital process. The simulation results show that this converter with on-chip current sensor can operate in 1.5 MHz with supply voltage varied from 4.5 to 3.5 V, which is suitable for single-cell lithium-ion battery supply applications, with a off-chip capacitor and a off-chip inductor. The maximum power efficiency is 94.3% for load current varied from 50 to 500 mA. The supply voltage range of the converter can be adjusted from 3.5V to 4.5V. For line regulation simulation, the output voltage is always stabilized at the preset value with a maximum output ripple of . For load regulation simulation by varying the output current from 0.5A heavy load to 0.1A light load, the maximum output ripple is merely . The combined regulation has been simulated with both line regulation and load regulation, and the maximum output ripple is . There are three supply voltages of 3.8V, 3.6V, and 4V simulated along with process variation to generate a maximum output ripple of . For temperature variation of ~ , the maximum output ripple is . All above results confirm the excellence of the proposed circuit compared with the commercialized chips. The chip size of the proposed circuit is which is merely 53.66% of those of its predecessors. With such tiny size, the proposed converter is excellent for low cost but high efficiency portable applications to greatly enhance the product competitiveness.
Kuo-ChunWu e 吳國鈞. "Average-Current-Mode Buck-Boost DC-DC Converter with Full-Wave Current Sensor". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/12640023247879599750.
國立成功大學
電機工程學系碩博士班
101
Due to the growth of consumer electronics market, there are more and more studies in energy saving to prolong service life of electronic products. Because the output voltage of batteries decreases with time (e.g., Li-ion: 2.7–4.2 V), it may be higher or lower than the required supply voltage (e.g., 3.3V). To use the entire battery output voltage range, a non-inverting buck-boost dc-dc converter is a good choice. In this work, an average-current-mode non-inverting buck-boost dc-dc converter with the advantages of high power efficiency, faster transient response, and excellent noise immunity is introduced. Furthermore, a novel current sensing scheme, which can reduce noise and then improve system stability, is proposed. The die area of this chip is 2.3x1.86 , which is fabricated by using Taiwan Semiconductor Manufacturing Company (TSMC) 0.35μm 2P4M 5V mixed-signal polycide process. The converter output is regulated to 3.3V, when the loading current is 50 mA to 300 mA and the input voltage is 2.5V to 5V.
Chen, Jian-Hao, e 陳建豪. "Constant-Frequency Hysteresis-Current-Controlled DC-DC Converter with Active-Current-Sensing Techniques". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/3j6734.
Chiang, Ta-Jen, e 江大任. "Realization of a ZVS Current-Fed Boost Converter for Bi-directional DC/DC Converter". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/95229697296824328865.
中原大學
電機工程研究所
105
Thesis is to improve the boost conversion characteristics of the bidirectional full-bridge DC / DC converters and to maintain the excellent behavior of the phase-shifted buck conversion. Quasi-resonant full-bridge current-fed method is adopted to achieve the boost energy conversion with constant-off time control, while the switches are commutated at zero-voltage-switching (ZVS) to enhance the conversion efficiency. In this study, a full-bridge bidirectional DC / DC converter with output power of 1 kW is implemented to verify the proposed method, where the low-side DC bus is 48V and the high-side DC bus 380V. Finally, the phase-shifted buck conversion is also tested in the same circuit topology. The experimental results confirm that the maximum conversion efficiency of the boost mode is 90%, while that of the buck mode is 88%.
Hsu, Hsin-Ju, e 許昕茹. "Automatic Layout Synthesis Tool for DC-DC Current-Mode Buck Converter". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/64617872141924593723.
國立中央大學
電機工程學系
105
In our days, lots of electronic product are made of analog/mixed-signal (AMS) intergrated circuits (ICs), such as portable devices, medical equipment, communication product and automobile electronics etc. Nowadays, with the growing demands for portable devices, Time-to-Market cycle still keeps shrinking. Electronic design automation (EDA) tools are the keys to speed up the device process. There are many existing EDA tools for digital circuits on the market. However, the EDA tools for AMS circuits are still not popular. Because analog circuits are often sensitive to small signals response, their layouts are often manually designed by experienced designers. Therefore, AMS circuit design has become the bottleneck in SoC design flow. In order to increase the circuit performance and shorten design process, we perpose an automatic layout synthesis tool for DC-DC current-mode control buck converters in the thesis. This synthesis tool is able to generate the final layout of the target circuit automatically from given specification. The design environment is developed with C++ and Tcl/Tk programming language. The required layout can be generated in Laker automatically and pass the DRC/LVS verification. The post-layout simulation results also satisfy the required specification.
Wu, Shing-Lih, e 吳行立. "The Research of DC to DC Converter for Current Sharing Control". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/45090815512461023180.
逢甲大學
電機工程所
93
Abstract The advance of VLSI brings a new challenge for transfering high power to microprocessors. As Intel predicted, the microprocessors will operate at low voltage, high current and high slew rate, with the continuous increase in the speed and transistor number within the chips. To increase transistor number and processor speed ,the improvement of current demands and transition speed is much more desirable. In order to reduce power consumption, the supply voltage of the microprocessors have been decreased. For future microprocessors with low voltage and high current, can not only increae computation speed and performance, but can also increase slew rate of output current. In order to improve the efficiency of synchronous buck converter, multiphase interleave synchronous buck converter is widely used. In this paper, a multiphase interleave technology ,which can used in synchronous buck converter, is proposed.
Hsuan-ChingSu e 蘇軒瑨. "High Step-Up Current-Fed DC-DC Converter with Coupled Inductor". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/08113321242325984541.
國立成功大學
電機工程學系碩博士班
101
In this thesis, a novel high step-up current-fed DC-DC converter with coupled inductor has been proposed. This converter has advantages of simple structure and high efficiency. In addition, output-voltage stacking technique has been adopted, so that the voltage stress on each power device can be reduced. Besides, the converter is a current-fed type which can reduce input current ripple. By the means that two capacitors have been charged simultaneously and been discharged in series, it can achieve the purpose of high voltage conversion ratio. The converter can get high voltage ratio about 16 times by operating duty cycle above 0.5. The highest conversion efficiency of the proposed converter is 96.06%. Moreover, the conversion efficiencies are above 95% from light load to full load. First, different types of high step-up converters are introduced. Second, the analysis of operating principle of the proposed converter is performed. Then, design the power devices’ parameters of the main circuit. Finally, a prototype circuit with 24 V input voltage, 400 V output voltage and 200 W output power is implemented to verify the performance of the proposed converter.
Zone-ChingLee e 李宗慶. "Implementation of a Current-Fed High Step-Up DC-DC Converter". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/73581722044410605304.
國立成功大學
電機工程學系碩博士班
98
High step-up techniques have been explored and developed for boost converter applications. However, many of the converters have the problem of high pulsating input currents from the power source, which often is a disturbance on the DC output of a renewable power source, like fuel cells or solar PV cells. Concerned is the significant impact on fuel cell diffusion layer or the output power of solar PV cells. For this reason, high step-up of current-fed configuration converter is considered more suitable for renewable source generation system, especially for the fuel cells. Based on SEPIC converter and cascade topology, this thesis proposes a current-fed high voltage step-up DC-DC converter. The first inductor of the proposed converter is operated in continuous conduction mode, which has lower pulsating input current and thus reduced current ripple. The reduced current ripple can minimize the input electrolytic capacitor needed and extend its life-time as well as reliability. The second inductor employed in the proposed circuit is a coupled inductor to achieve much higher voltage conversion ratio and avoid operation at extreme duty ratio via a proper turn ratio. In addition to, the voltage spike on the main switch can being clamped, the leakage inductance of the coupled inductor is designed to be recycled to output load. Therefore, with reduced voltage stress on the power switch, its power-rating and on resistance can be lower to further decrease both switching and conduction losses. Moreover, synchronous rectifier is applied into the front-end of the proposed converter to further decrease conduction losses. The operation principles and analyses of the steady-state and voltage stress on each semiconductor device are presented in this thesis. Feasibility and effectiveness of the proposed circuit are verified via computer simulations and practical experiments.
Liu, Ti-Ti, e 劉玓玓. "A Current Domain Boost DC-DC Converter for LED Driver Applications". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/44033038272983008687.
國立交通大學
電機與控制工程系所
96
In the past, the backlight module for liquid crystal displays (LCD) consisted mainly of cold cathode fluorescent lamp (CCFL). However, with the greatly improving technology of light emitting diode (LED) process, the benefit for LED backlight is more and more obviously such as high color saturation, longer product life and none hydrargyrum. Thus, people are trying to replace CCFL to RGB LED to reach the high quality images in displays targeted for market. Two most popular approaches for LED driver implementation are an inductor-less charge pump converter and an inductor-based converter. Although the cost and EMI problem of a charge pump is low, the load ability and efficiency is poor compared to those of a switching regulator. In the application of high brightness LED driver, the high power characteristics are needed, since the number of LEDs for backlight implementation is above hundreds. The highly efficient voltage regulators are needed for energy transform, because of low power consumption in converters. Moreover, owing to driving a large number of LEDs in one controller, the cost of the system is reduced. This thesis presents a current domain DC-DC boost converter for LED application with 12V input voltage and 48V output voltage. The boost voltage regulator utilizes a pulse width modulation (PWM) current programmed control method, which transfers the control signal in current domain to improve the transient response. The disadvantage of this method is big static error. The supply voltage of the controller is in the range from 2.5V to 3.6V. The best efficiency of the converter is 92% at 300mA load current. This converter design is simulated and fabricated in UMC 0.35�慆 embedded high voltage 3.3V/18V CMOS technology.
Pai-YiWang e 王派益. "A Current-Mode DC-DC Buck Converter with Variable-Frequency Controller". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/53741969966548917400.
國立成功大學
電機工程學系碩博士班
98
A current-mode buck converter with integrated analog variable-frequency controller (VFC) is implemented in this thesis. With the highly growing market of the portable devices, a compact, fast, low cost and high efficiency regulator is needed in power management solutions. Design of the regulator with small inductor can significantly reduce the PCB size and cost; and it is inherently faster than general solutions due to higher filtering bandwidth. But small inductor makes higher output voltage ripple, thus the design of switching frequency is limited by the rated output voltage ripple; faster switching frequency though effectively reduces the output voltage ripple without increasing the output capacitance, but introduces more frequency-dependent power loss such as switching loss and dead-time loss into regulator. By adapting VFC, which can be easily integrated in a chip without complex control circuts, the efficiency can be optimized under rated output voltage ripple with small inductor value. Furthermore, the proposed current-mode regulator provides an improvement of the current sensor, reducing the controller power loss while maintaining sensing accuracy, and eliminating the sensed noise, providing better sensed signal quality to the feedback loop, significantly promoting the performance of current-mode switching regulator. This current-mode buck regulator is fabricated with TSMC 0.35um 3.3/5V Mixed-Signal CMOS process. The total chip area is about 1.06 x 0.995 mm2. Verification results show that power saving at least 5mW and 20mW during light load and heavy load individually.
Li, Kuang-Chieh, e 李光傑. "Research on Current Detection Improvement Method for DC-DC Buck Converter". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/cwjzm6.
國立臺灣海洋大學
電機工程學系
105
In recent years, the application of electronic devices is widely spread. DC-DC converters are increasingly important due to their use for power control of the electronic devices. Because current detection significantly affects the quality control of DC-DC buck converters, this thesis is aimed to research an improvement strategy on current detection to overcome the disadvantages of the commonly used current detection scheme. The thesis focuses on finding a current detection scheme, named inductor DC resistance sensing , for the purposes of low cost and low power conversion loss, as well as its strength and weakness as compared to the resistor sensing method. The inductor DC resistance sensing method uses a series resister-capacitor circuit connected with an inductor (parasitic DC resistance) in parallel, which doesn’t alter the converter’s structure and affect little power conversion efficiency, thus is suitable for current detection of low power loss DC-DC converters. Experimental results show that the resistor sensing method is better if system needs precise current detection, available space is large enough and power loss is endurable. Otherwise, the inductor DC resistance sensing method is the better choice for current detection.