Dissertations / Theses on the topic 'High Frequency Converter'
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Liu, Kwang-Hwa. "High-frequency quasi-resonant converter techniques." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/74737.
Full textPh. D.
Xu, Ping. "High-frequency Analog Voltage Converter Design." PDXScholar, 1994. https://pdxscholar.library.pdx.edu/open_access_etds/4891.
Full textBalakrishnan, Anand Kumar. "Soft switched high frequency ac-link converter." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3156.
Full textLI, QUAN, and q. li@cqu edu au. "HIGH FREQUENCY TRANSFORMER LINKED CONVERTERS FOR PHOTOVOLTAIC APPLICATIONS." Central Queensland University. N/A, 2006. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20060830.110106.
Full textSi, Dang Huy Quoc. "A new implementation of high frequency, high voltage direct power converter." Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430219.
Full textAhmad, Nisar. "Design and Implementation of a High Frequency Flyback Converter." Thesis, Mittuniversitetet, Avdelningen för elektronikkonstruktion, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-24598.
Full textSalazar, Nathaniel Jay Tobias. "High frequency AC power converter for low voltage circuits." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/77026.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 74-76).
This thesis presents a novel AC power delivery architecture that is suitable for VHF frequency (50-100MHz) polyphase AC/DC power conversion in low voltage integrated circuits. A complete AC power delivery architecture was evaluated demonstrating the benefits of delivering power across the interconnect at high voltage and lower current with on- or over-die transformation to low voltage and high current. Two approaches to polyphase matching networks in the transformation stage are compared: a 3-phase system with separate single-phase matching networks and individual full bridge rectifiers, and a 3-phase delta-to-wye matching network and a 3-phase rectifier bridge. In addition, a novel switch-capacitor rectifier capable of 3V, 1W output, was evaluated as an alternative circuit to the diode rectifiers. A 50MHz prototype of each version of the system was designed and built for a 12:1 conversion ratio with 24Vpp line-to-line AC input, 2V DC output and 0.7W output power. The measured overall system efficiency is about 63 % for the 3-phase delta system. Although the application is intended for an integrated CMOS implementation, this thesis primarily focuses on discrete PCB level realizations of the proposed architectures to validate the concept and provide insights for future designs.
by Nathaniel Jay Tobias Salazar.
M.Eng.
Van, Der Kogel André, and Niklas Österlund. "High frequency dc/dc power converter with galvanic isolation." Thesis, Linköpings universitet, Fysik och elektroteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-128831.
Full textReusch, David Clayton. "High Frequency, High Power Density Integrated Point of Load and Bus Converters." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/26920.
Full textPh. D.
Davari, Pooya. "High frequency high power converters for industrial applications." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/62896/1/Pooya_Davari_Thesis.pdf.
Full textLi, Quan, and q. li@cqu edu au. "DEVELOPMENT OF HIGH FREQUENCY POWER CONVERSION TECHNOLOGIES FOR GRID INTERACTIVE PV SYSTEMS." Central Queensland University. School of Advanced Technologies & Processes, 2002. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20020807.152750.
Full textZhang, Zhemin. "High-frequency Quasi-square-wave Flyback Regulator." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/77434.
Full textPh. D.
Bai, Yuming. "Optimization of Power MOSFET for High-Frequency Synchronous Buck Converter." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/28915.
Full textPh. D.
Ward, Gillian Anne. "Design of a multi-kilowatt, high frequency, DC-DC converter." Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274596.
Full textSagneri, Anthony (Anthony David). "Design of a Very High Frequency dc-dc boost converter." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/38664.
Full textIncludes bibliographical references (p. 167-169).
Passive component volume is a perennial concern in power conversion. With new circuit architectures operating at extreme high frequencies it becomes possible to miniaturize the passive components needed for a power converter, and to achieve dramatic improvements in converter transient performance. This thesis focuses on the development of a Very High Frequency (VHF, 30 - 300 MHz) dc-dc boost converter using a MOSFET fabricated from a typical power process. Modeling and design studies reveal the possibility of building VHF dc-dc converters operable over the full automotive input voltage range (8 - 18 V) with transistors in a 50 V power process, through use of newly-developed resonant circuit topologies designed to minimize transistor voltage stress. Based on this, a study of the design of automotive boost converters was undertaken (e.g., for LED headlamp drivers at output voltages in the range of 22 - 33 V.) Two VHF boost converter prototypes using a [Phi]2 resonant boost topology were developed. The first design used an off the shelf RF power MOSFET, while the second uses a MOSFET fabricated in a BCD process with no special modifications.
(cont.) Soft switching and soft gating of the devices are employed to achieve efficient operation at a switching frequencies of 75 MHz in the first case and 50 MHz in the latter. In the 75 MHz case, efficiency ranges to 82%. The 50 MHz converter, has efficiencies in the high 70% range. Of note is low energy storage requirement of this topology. In the case of the 50 MHz converter, in particular, the largest inductor is 56 nH. Finally, closed-loop control is implemented and an evaluation of the transient characteristics reveals excellent performance.
by Anthony Sagneri.
S.M.
Neveu, Florian. "Design and implementation of high frequency 3D DC-DC converter." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0133/document.
Full textUltimate integration of power switch-mode converter relies on two research paths. One path experiments the development of switched-capacitor converters. This approach fits silicon integration but is still limited in term of power density. Inductive DC-DC architectures of converters suffer by the values and size of passive components. This limitation is addressed with an increase in frequency. Increase in switching losses in switches leads to consider advanced technological nodes. Consequently, the capability with respect to input voltage is then limited. Handling 3.3 V input voltage to deliver an output voltage in the range 0.6 V to 1.2 V appears a challenging specification for an inductive buck converter if the smallest footprint is targeted at +90 % efficiency. Smallest footprint is approached through a 3D assembly of passive components to the active silicon die. High switching frequency is also considered to shrink the values of passive components as much as possible. In the context of on-chip power supply, the silicon technology is dictated by the digital functions. Complementary Metal-Oxide- Semiconductor (CMOS) bulk C40 is selected as a study case for 3.3 V input voltage. 3.3 V Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) features poor figure of merits and 1.2 V standard core, regular devices are preferred. Moreover future integration as an on-chip power supply is more compatible. A three-MOSFET cascode arrangement is experimented and confronted experimentally to a standard buck arrangement in the same technology. The coupled-phase architecture enables to reduce the switching frequency to half the operating frequency of the passive devices. +100MHz is selected for operation of passive devices. CMOS bulk C40 offers Metal-Oxide-Metal (MOM) and MOS capacitors, in density too low to address the decoupling requirements. Capacitors have to be added externally to the silicon die but in a tight combination. Trench-cap technology is selected and capacitors are fabricated on a separate die that will act as an interposer to receive the silicon die as well as the inductors. The work delivers an object containing a one-phase buck converter with the silicon die flip-chipped on a capacitor interposer where a tiny inductor die is reported. The one-phase demonstrator is suitable for coupled-phase demonstration. Standard and cascode configurations are experimentally compared at 100 MHz and 200 MHz switching frequency. A design methodology is presented to cover a system-to-device approach. The active silicon die is the central design part as the capacitive interposer is fabricated by IPDiA and inductors are provided by Tyndall National Institute. The assembly of the converter sub-parts is achieved using an industrial process. The work details a large set of measurements to show the performances of the delivered DC/DC converters as well as its limitations. A 91.5% peak efficiency at 100MHz switching frequency has been demonstrated
Li, Qiang. "Low-Profile Magnetic Integration for High-Frequency Point-of-Load Converter." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/28637.
Full textPh. D.
Pilawa-Podgurski, Robert C. N. "Design and evaluation of a very high frequency dc/dc converter." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41545.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 139-143).
This thesis presents a resonant boost topology suitable for very high frequency (VHF, 30-300 MHz) dc-dc power conversion. The proposed design is a fixed frequency, fixed duty ratio resonant converter featuring low device stress, high efficiency over a wide load range, and excellent transient performance. A 110 MHz, 23 W experimental converter has been built and evaluated. The input voltage range is 8-16 V (14.4 V nominal), and the selectable output voltage is between 22-34 V (33 V nominal). The converter achieves higher than 87% efficiency at nominal input and output voltages, and maintains efficiency above 80% for loads as small as 5% of full load. Furthermore, efficiency is high over the input and output voltage range. In addition, a resonant gate drive scheme suitable for VHF operation is presented, which provides rapid startup and low-loss operation. The converter regulates the output using high-bandwidth on-off hysteretic control, which enables fast transient response and efficient light load operation. The low energy storage requirements of the converter allow the use of coreless inductors, thereby eliminating magnetic core loss and introducing the possibility of integration. The target application of the converter is the automotive industry, but the design presented here can be used in a broad range of applications where size, cost, and weight are important, as well as high efficiency and fast transient response.
by Robert C.N. Pilawa-Podgurski.
M.Eng.
Burkhart, Justin (Justin Michael). "Design of a very high frequency resonant boost DC-DC converter." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/60157.
Full textIncludes bibliographical references (p. 163-164).
THIS thesis explores the development of a very high frequency DC-DC resonant boost converter. The topology examined features low parts count and fast transient response but suffers from higher device stresses compared to other topologies that use a larger number of passive components. A new design methodology for the proposed converter topology is developed. This design procedure - unlike previous design methodologies for similar topologies - is based on direct analysis of the topology and does not rely on lengthy time-domain simulation sweeps across circuit parameters to identify good designs. Additionally, a method to design semiconductor devices that are suitable for use in the proposed VHF power converter is presented. When the main semiconductor switch is fabricated in a integrated power process where the designer has control over the device layout, large performance gains can be achieved by considering parasitics and loss mechanisms that are important to operation at VHF when designing the device. A method to find the optimal device for a particular converter design is presented. The new design methodology is combined with the device optimization technique to enable the designer to rapidly find the optimal combination of converter and device design for a given specification. To validate the proposed converter topology, design methodology, and device optimization, a 75 MHz prototype converter is designed and experimentally demonstrated. The performance of the prototype closely matches that predicted by the design procedure, and achieves good efficiency over a wide input voltage range.
by Justin Burkhart.
S.M.
Musabeyoglu, Ahmet Can. "A zero-voltage switching technique for high frequency buck converter ICs." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113122.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 59-60).
This thesis explores a zero-voltage switching (ZVS) method that can be used to decrease the frequency dependent losses in a buck converter. The specific application for this thesis was a buck converter IC with an input voltage of up to 42V. The method utilizes the addition of an auxiliary circuit composed of a helper inductor and two helper power MOSFETs that compliment the switching transition of a conventional synchronous buck converter topology. It is shown in this thesis that by using the described topology, the switching losses of the high-side power MOSFET in a synchronous buck converter can be reduced by up to 45%. Furthermore, it is shown that a similar helper circuit could be used to reduce the gate drive losses for both power MOSFETs in a synchronous buck converter by up to 60%. Since the method requires the use of an additional helper inductor with a small value (10-50 nH), various methods to integrate this inductor into an IC package are investigated. 0.35[mu]m BiCMOS technology was used to simulate and analyze the merits of the described topology and compare it to the LT8697, a hard-switched synchronous buck converter IC.
by Ahmet Can Musabeyoglu.
M. Eng.
Vulovic, Marko. "Digital Control of a High Frequency Parallel Resonant DC-DC Converter." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/35934.
Full textMaster of Science
Su, Yipeng. "High Frequency, High Current 3D Integrated Point-of-Load Module." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51248.
Full textPh. D.
Ji, Shu. "High Frequency, High Power Density GaN-Based 3D Integrated POL Modules." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/19286.
Full textToday, this concept has been demonstrated at a level less than 5A and a power density around 300-700W/in3 by using silicon-based power semiconductors. This might address the need of small hand-held equipment such as PDAs and smart phones. However, it is far from meeting the needs for applications, such as netbook, notebook, desk-top and server applications where tens and hundreds of amperes are needed.
After 30 years of silicon MOSFET development, the silicon has approached its theoretical limits. The recently emerged GaN transistors as a possible candidate to replace silicon devices in various power conversion applications. GaN devices are high electron mobility transistors (HEMT) and have higher band-gap, higher electron mobility, and higher electron velocity than silicon devices, and offer the potential benefits for high frequency power conversions. By implementing the GaN device, it is possible to build the POL converter that can achieve high frequency, high power density, and high efficiency at the same time. GaN technology is in its early stage; however, its significant gains are projected in the future. The first generation GaN devices can outperform the state-of-the-art silicon devices with superior FOM and packaging.
The objective of this work is to explore the design of high frequency, high power density 12 V input POL modules with GaN devices and the 3D integration technique. This work discusses the fundamental differences between the enhancement mode and depletion mode GaN transistors, the effect of parasitics on the performance of the high frequency GaN POL, the 3D technique to integrate the active layer with LTCC magnetic substrate, and the thermal design of a high density module using advanced substrates with improved thermal conductivity.
The hardware demonstrators are two 12 V to 1.2 V highly integrated 3D POL modules, the single phase 10 A module and two phase 20 A module, all built with depletion mode GaN transistors and low profile LTCC inductors.
Master of Science
Asgarifar, Hajarossadat. "Application of high voltage, high frequency pulsed electromagnetic field on cortical bone tissue." Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/53105/1/Hajarossadat_Asgarifar_Thesis.pdf.
Full textSTEPHANE, YANNICK NJIOMOUO. "3D High Frequency Modelling of Motor Converter and Cables in Propulsion Systems." Thesis, KTH, Elektroteknisk teori och konstruktion, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-160637.
Full textAnvandningen av kraftomvandlare i jarnvagstraktionssystem introducerar hogfrekvens elektromagnetisk interferens (EMI) i framdrivningssystemet, vilket orsakar elektromagnetiska kompatibilitetsproblem (EMC). Dessa hogfrekvensfenomen orsakas av snabba variationer i strom och spanning under omkopplingsoperationer i kraftomvandlare. Hogfrekvensstrommarna alstrar elektromagnetiska (EM) storningar, som kan paverka funktionaliteten hos det elektriska drivsystemet. Storningar vid kraft- och ljudfrekvenser kan paverka signal- och kontrollsystemen, medan hogfrekventa strommar injiceras i kabelskarmar kan skada kablarna. For att sakerstalla kompatibiliteten mellan EMC-kraven, vad galler ledningsbundna och utsanda storningar, och specikationerna for signalsystemets infrastruktur ar det nodvandigt att utfora 3D-modellering av drivsystemet, for att redan under designfasen av framdrivningssystemet kunna forutsaga de elektromagnetiska storningarna. CST, som ar ett elektromagnetiskt analysverktyg, anvands for att skapa 3D-modellen av omriktarmodulen och kablarna. Modellen gor det mojligt att ta med de parasitiska egenskaperna hos IGBT, ledningsmoduler och motorkablar. Inverkan av olika jordningssystemen analyseras. Modellen forutsager det elektromagnetiska faltet vid olika punkter inuti omriktarmodulen och i dess narhet.
Cliffe, Robert J. "High power high frequency DC-DC converter topologies for use in off-line power supplies." Thesis, Loughborough University, 1996. https://dspace.lboro.ac.uk/2134/7305.
Full textTao, Fengfeng. "Advanced High-Frequency Electronic Ballasting Techniques for Gas Discharge Lamps." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/25978.
Full textPh. D.
Wen, Yangyang. "MODELING AND DIGITAL CONTROL OF HIGH FREQUENCY DC-DC POWER CONVERTERS." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3671.
Full textPh.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering PhD
Qiu, Yang. "High-Frequency Modeling and Analyses for Buck and Multiphase Buck Converters." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29804.
Full textPh. D.
Tolstoy, Georg. "High-Efficiency SiC Power Conversion : Base Drivers for Bipolar Junction Transistors and Performance Impacts on Series-Resonant Converters." Doctoral thesis, KTH, Elektrisk energiomvandling, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-168163.
Full textQC 20150529
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.
Full textSun, Bingyao. "High-Frequency Oriented Design of Gallium-Nitride (GaN) Based High Power Density Converters." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/85054.
Full textPh. D.
Chu, Alex. "Evaluation and Design of a SiC-Based Bidirectional Isolated DC/DC Converter." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/81994.
Full textMaster of Science
Jiao, Yang. "High Power High Frequency 3-level NPC Power Conversion System." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/56653.
Full textPh. D.
Song, Yu Jin. "Analysis and design of high frequency link power conversion systems for fuel cell power conditioning." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/2678.
Full textHou, Dongbin. "Very High Frequency Integrated POL for CPUs." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/77608.
Full textPh. D.
Gilham, David Joel. "Packaging of a High Power Density Point of Load Converter." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/19325.
Full textOne issue with current converters is the large volume of the passive components. Increasing the switching frequency to the megahertz range is one way to reduce to volume of these components. The other way is to fundamentally change the way these inductors are designed. This work will explore the use of low temperature co-fired ceramic (LTCC) tapes in the magnetic design to allow a low profile planar inductor to be used as a substrate. LTCC tapes have excellent properties in the 1-10 MHz range that allow for a high permeability, low loss solution. These tapes are co-fired with a silver paste as the conductor. This paper looks at ways to reduce dc resistance in the inductor design through packaging methods which in turn allow for higher current operation and better heavy load efficiency. Fundamental limits for LTCC technologies are pushed past their limits during this work. This work also explores fabrication of LTCC inductors using two theoretical ideas: vertical flux and lateral flux. Issues are presented and methods are conceived for both types of designs. The lateral flux inductor gives much better inductance density which results in a much thinner design.
It is found that the active devices must be shielded from the magnetic substrate interference so active layer designs are discussed. Alumina and Aluminum Nitride substrates are used to form a complete 3D integration scheme that gives excellent thermal management even in natural convection. This work discusses the use of a stacked power technique which embeds the devices in the substrate to give double sided cooling capabilities. This fabrication goes away from traditional photoresist and solder-masking techniques and simplifies the entire process so that it can be transferred to industry. Time consuming sputtering and electroplating processes are removed and replaced by a direct bonded copper substrate which can have up to 8 mil thick copper layers allowing for even greater thermal capability in the substrate. The result is small footprint and volume with a power density 3X greater than any commercial product with comparable output currents. A two phase coupled inductor version using stacked power is also presented to achieve even higher power density.
As better device technologies come to the marketplace, higher power density designs can be achieved. This paper will introduce a 3D integration design that includes the use of Gallium Nitride devices. Gallium Nitride is rapidly becoming the popular device for high frequency designs due to its high electron mobility properties compared to silicon. This allows for lower switching losses and thus better thermal characteristics at high frequency. The knowledge learned from the stacked power processes gives insight into creating a small footprint, high current ceramic substrate design. A 3D integrated design is presented using GaN devices along with a lateral flux inductor. Shielded and Non-Shielded power loop designs are compared to show the effect on overall converter efficiency. Thermal designs and comparisons to PCB are made using thermal imaging. The result is a footprint reduction of 40% from previous designs and power densities reaching close to 900W/in3.
Master of Science
Li, Bin. "High Frequency Bi-directional DC/DC Converter with Integrated Magnetics for Battery Charger Application." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/97874.
Full textPHD
Xiong, Yali. "MODELING AND ANALYSIS OF POWER MOSFETS FOR HIGH FREQUENCY DC-DC CONVERTERS." Doctoral diss., University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3589.
Full textPh.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering PhD
Anton, Gagner, and Nino Hebib. "FPGA Software Development for Control Purposes of High-Frequency Switching Power Converters." Thesis, Linköpings universitet, Fysik och elektroteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-133213.
Full textFei, Chao. "Microcontroller (MCU) Based Simplified Optimal Trajectory Control (SOTC) for High-Frequency LLC Resonant Converters." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/78117.
Full textMaster of Science
Sheng, Honggang. "A High Power Density Three-level Parallel Resonant Converter for Capacitor Charging." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/37667.
Full textPh. D.
Wen, Hao. "High-Efficiency and High-Frequency Resonant Converter Based Single-Stage Soft-Switching Isolated Inverter Design and Optimization with Gallium-Nitride (GaN)." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/105134.
Full textDoctor of Philosophy
Inverters can convert dc voltage to ac voltage and typically people use two-stage approach with isolated dc-dc stage and dc-ac stage. However, this two-stage configuration suffers from more components count, more complex control and tend to have lower efficiency and lower power density. Therefore, the single-stage solution with dc-rectified sine wave stage and a line frequency unfolder becomes appealing. The unfolder circuit is to unfold the rectifier sine wave to an ac sine wave at the output. Since the unfolder is at line frequency and can be considered lossless, the key design is for the dc-rectified sine stage. The resonant converter featured for soft switching seems to be a good candidate. However, the inverter needs soft switching for the whole range and an enough wide voltage gain, which makes the design difficult, especially the target is high efficiency for the overall inverter. This dissertation aims to provide solutions for a high-efficiency, high-frequency resonant converter based single-stage soft-switching isolated inverter design. The LLC and LCLCL resonant converters are applied as the isolated dc-rectified sine stage with variable frequency modulation (VFM). Therefore, the rectified sine wave generation consists of many dc-dc conversion with different switching frequencies and an efficient dc-rectified sine stage design needs each dc-dc conversion to be with high efficiency. The design considerations and optimization methods for the LLC dc-dc conversion are firstly investigated. Based on these approaches, a MHz LLC converter based isolated inverter is designed with proposed hybrid modulation method. To further improve the light load performance, a MHz LCLCL converter based isolated inverter topology is proposed. The paralleled LC inside the LCLCL resonant tank can naturally create a zero voltage gain point which shows superior characteristics for rectified sine wave generation. Moreover, the LCLCL resonant converter based topology has bi-directional capability as well so it can work well for ac voltage to dc voltage conversion.
Yan, Ning. "High-frequency Current-transformer Based Auxiliary Power Supply for SiC-based Medium Voltage Converter Systems." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/101507.
Full textM.S.
Recently, 10 kV silicon carbide (SiC) MOSFET receives strong attention for medium voltage applications. Asit can switch at very high speed, e.g. > 50 V/ns, the converter system can operate at higher switching frequency condition with very small switching losses compared to silicon (Si) IGBT [8]. However, the fast dv/dt noise also creates the common mode current via coupling capacitors distributed inside the converter system, thereby introducing lots of electromagnetic interference (EMI) issues. Such issues typically occur within the gate driver power supplies due to the high dv/dt noises across the input and output of the supply. Therefore, the ultra-small coupling capacitor (<5 pF) of a gate driver power supply is strongly desired.[37] To satisfy the APS demands for high power modular converter system, a solution is proposed in this thesis. This work investigates the design of 1 MHz isolated APS using gallium nitride (GaN) devices with medium voltage insulation reinforcement. By increasing switching frequency, the overall converter size could be reduced dramatically. To achieve a low Ccm value and medium voltage insulation of the system, a current-based transformer with a single turn on the sending side is designed. By adopting LCCL-LC resonant topology, a current source is formed as the output of sending side circuity, so it can drive multiple loads importantly with a maximum of 120 W. At the same time, ZVS can use realized with different load conditions. The receiving side is a regulated stage, so the output voltage can be easily adjusted and it can operate in a load fault condition. Different insulation solutions will be introduced and their effect on Ccm will be discussed. To further reduce Ccm, shielding will be introduced. Overall, this proposed APS can achieve a breakdown voltage of over 20 kV and PDIV up to 16.6 kV with Ccm<5 pF. Besides, multi-load driving ability is able to achieve with a maximum of 120 W. ZVS can be realized. In the end, the experiment results will be provided.
Sinyan, Ensa. "Modeling of Resonances in a Converter Module including Characterization of IGBT Parasitics." Thesis, KTH, Elektrisk energiomvandling, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-133354.
Full textIuravin, Egor. "Transformer Design For Dual Active Bridge Converter." Miami University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=miami1532601248778308.
Full textDanekar, Abhishek V. "Analysis and Design of High-Frequency Soft-Switching DC-DC Converter for Wireless Power Charging Applications." Wright State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=wright1493990400812363.
Full textSun, Keyao. "Protection, Control, and Auxiliary Power of Medium-Voltage High-Frequency SiC Devices." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/103743.
Full textDoctor of Philosophy
The wide bandgap semiconductor enables next-generation power electronics systems with higher efficiency and higher power density which will reduce the space, weight, and cost for power supply and conversion systems, especially for renewable energy. However, by pushing the system voltage level higher to medium-voltage of tens of kilovolts, although the system has higher efficiency and simpler control, the reliability drops. This dissertation, therefore, focusing on solving the possible overcurrent, overvoltage, and gate failure issues of the power electronics system that is caused by the high voltage and high electromagnetic interference environment. By utilizing the inductance of the device, a dual-protection method is proposed to prevent the overcurrent problem. The overcurrent fault can be detected within tens of nanoseconds so that the device will not be destroyed because of the huge fault current. When multiple devices are connected in series to hold higher voltage, the voltage sharing between different devices becomes another issue. The proposed modeling and control method for series-connected devices can balance the shared voltage, and make the control system stable so that no overvoltage problem will happen due to the non-evenly distributed voltages. Besides the possible overcurrent and overvoltage problems, losing control of the devices due to the unreliable auxiliary power supply is another issue. This dissertation proposed a scalable auxiliary power network with high efficiency, high immunity to electromagnetic interference, and high reliability. In this network, a wireless power transfer converter is designed to provide enough insulation and isolation capability, while a switched capacitor converter is designed to transfer voltage from several kilovolts to tens of volts. With the proposed overcurrent protection method, voltage sharing control, and reliable auxiliary power network, systems utilizing medium-voltage wide-bandgap semiconductor will have higher reliability to be implemented for different applications.
Zhao, Shishuo. "High Frequency Isolated Power Conversion from Medium Voltage AC to Low Voltage DC." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/74969.
Full textMaster of Science
Yang, Liyu. "Modeling and Characterization of a PFC Converter in the Medium and High Frequency Ranges for Predicting the Conducted EMI." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/35226.
Full textMaster of Science