quarta-feira, 5 de outubro de 2022
THE SMART: PROVIDING SERVICE TO THE ELECTRIC NETWORK AND ADDRESSING THE RELIABILITY CHALLENGES THROUGH POWER ROUTING by Dr Marco Liserre de la Univ de KIEL
sábado, 17 de setembro de 2022
Transferencia de energía inalámbrica para alimentación de implantes médicos: diseño y optimización del enlace inductivo y de la topología conversora de energía Author Rodriguez Tallón, Juan Carlos--Master thesis
Title Transferencia de energía inalámbrica para alimentación de implantes médicos: diseño y optimización del enlace inductivo y de la topología conversora de energía
Author/s
Rodríguez Tallón, Juan Carlos
Contributor/s
Alou Cervera, Pedro
Jiménez Carrizosa, Miguel
Item
Type Thesis (Master thesis)
Masters title Electrónica Industrial
Date 2020
Subjects ElectronicsIndustrial EngineeringMedicine
Freetext Keywords Convertidores conmutados, WPT, IPT, Electrónica de Potencia, Electrónica Implantable
Faculty E.T.S.I. Industriales (UPM)
Department Automática, Ingeniería Eléctrica y Electrónica e Informática Industrial
Creative Commons Licenses Recognition - No derivative works - Non commercial
VIEW FULL THESIS:https://oa.upm.es/57840/1/TFM_JUAN_CARLOS_RODRIGUEZ_TALLON.pdf
quarta-feira, 7 de setembro de 2022
Doctoral Dissertation Multi Level Inverter System using Dual Output DC-DC Converter with High Gain Department of Electrical Engineering Graduate School, Chonnam National University BY Ibadullaev Anvar -2021
Doctoral Dissertation Multi Level Inverter System using Dual Output DC-DC Converter with High Gain Department of Electrical Engineering Graduate School, Chonnam National University Ibadullaev Anvar February 2021 Multi Level Inverter System using Dual Output DC-DC Converter with High Gain Ibadullaev Anvar Department of Electrical Engineering Graduate School Chonnam National University (Supervised by Professor Park SungJun)
(Abstract)
Electricity has a weighty and an important impact on the social, industrial
and economic developments of countries around the world because it is an
essential ingredient of modern civilization. XXI century civilization depends
on constant accessibility of this wealth in order to continue the present
form of life and developing. Recently, with the development of green energy
producing technology, the use of renewable sources such that photovoltaic
arrays(PV), fuel cell sources, etc. have been increasing rapidly. Depending
on the new research report published by “Markets and Market“, the inverter
market is projected to grow from USD 12.8 billion in 2020 to USD 26.5
billion by 2025. The inverter market is likely to exhibit lucrative growth
potential during the forecast period. The growth of the inverter market is
expected to be driven by continuosly rising number of industrial and
household solar rooftop installations.
This exponentially growth of the inverter selling segment can be
understood the entering of photovoltaic energy generation plants,
HEV(hybrid electric vehicles) and electric vehicles charging stations that has
brought new opportunities and challenges in the power electronics industry,
especially in terms of the research and development of the main traction
three phase AC motor drives. The multilevel inverter structure based
topologies gives the OK to these vehicles to hold out to high voltages and
power levels without using bulky and hard transformers. And also, the
limited installation spaces of the HEVs have also led to the requirement for
small size and power efficient inversion devices. Among end users, the
residential segment held the largest share of the inverter market in 2019.
Continuously rising electricity bills, coupled with supportive government
policies worldwide, have led to the increasing adoption of energy
conservation measures such as solar rooftop installations for controlling the
increased energy expenditure in residential applications. Countries such as
Japan, the United States, the Netherlands and Australia which are among
the prominent markets for residential rooftop solar installations, have widely
adopted solar inverters over conventional non-solar inverters. In addition,
countries such as Brazil, the United Kingdom, India and Mexico are
currently witnessing significant growth in the residential solar energy
market. In modern smart grid solutions, control technologies for the
consumption can response based on information about the electricity
generation and transmission system and prices in an automatic way to
improve the performance and reliability of the system. Demand for better
designed hardware topology and controllers is constantly rising as the
renewable energy market continues to sharply grow. In a typical residential,
or small factory utility photovoltaic arrays are connected in series, in
parallel or mixed type to form high DC voltage bus to can connect to
DC-AC inverter, which then is connected directly to single or three phase
AC Grid. Using renewable power generation systems established with step
up dc-dc converters is being popularized because of the rising demand of
zero pollution and eco friendly renewable energy sources. In this study, a
new constructed multi level inverter system using dual outptut DC–DC
converter was proposed to match a low DC voltage output sources, such as
photovoltaic source or fuel cell systems with single phase AC grid bus
lines. When comparing to other conventional multi level inverters, the
proposed multi level inverter has a decreased number of the
semiconductors, can create higher quality power with lower THD values,
has decreased and balanced voltage stress for dual output dc-dc converter
DC capacitors. The proposed topology requires a single DC source. In final,
the output viability of the proposed topology is described by simulation and
experimental results with 1 kW hardware prototype. While comparing to
another counterparts step-up DC–DC converters, the proposed Multi Level
Inverter System using Dual output DC-DC converter with high gain performs
higher gain and has lower inductor current ripple and lower drain-source
voltage stress for power semiconductors. Also the proposed dual output
DC-DC converter with high gain creates dual DC voltage output and voltage
stresses for the active and passive components have been decreased which
is the main superiority of the proposed topology. Steady state analysis in
CCM(continuous conduction mode) of the proposed topology is detailly
performed. And also the laboratory prototype of the proposed topology is
assembled using low voltage low power switches and low
capacitors. Output DC voltage and AC current control algorithm is performed
by employing DSP TMS320F28069F controller based control board. The
performance of the proposed topology is verified by a lot of simulation and
experimental results.
VIEW FULL DISSERTATION:
quarta-feira, 24 de agosto de 2022
Next-Generation Ultra-Compact/Efficient Data-Center Power Supply Modules A thesis submitted to attain the degree of DOCTOR OF SCIENCES of ETH ZURICH (Dr. sc. ETH Zurich) presented by GUSTAVO CARLOS KNABBEN
A thesis submitted to attain the degree of
DOCTOR OF SCIENCES of ETH ZURICH
(Dr. sc. ETH Zurich)
presented by
GUSTAVO CARLOS KNABBEN
MSc EE, UFSC
born on 23.05.1992
citizen of Joinville, Brazil
accepted on the recommendation of
Prof. Dr. Johann W. Kolar, examiner
Prof. Dr. Marcelo Lobo Heldwein, co-examiner
The increasingly-electric future requires next-generation power supplies
that are compact, efficient, low-cost, and ultra-reliable, even across
mains failures, to power mission-critical electrified processes. Hold-up time
requirements and the demand for ultra-high power density and minimum
production costs, in particular, drive the need for DC/DC power converters
with (i) a wide input voltage range, to reduce the size of the hold-up capacitor,
(ii) soft-switching over the full input-voltage and load ranges, to achieve low
losses that facilitate a compact realization, and (iii) complete PCB-integration
for low-cost manufacturing. Wide-bandgap power semiconductors, with
excellent on-resistance properties and low switching and reverse-recovery
losses, come along these requirements toward the conceptualization of nextgeneration
power-supply modules, but cannot alone catapult state-of-theart
converter technology to the performance baseline of future automotive,
automated manufacturing and hyperscale data-center applications. Instead,
the combination of wide-bandgap devices with proper converter topology,
control and magnetics design has proven to be the real enabler of power
supplies for the increasingly-electric future.
This thesis makes a case for the combination of these three features (widebandgap
devices, proper topology/control and advanced magnetics) as the
keys for paving the way toward next-generation power-supply modules.
Therefore, a suitable low-complexity circuit topology with improved control
scheme that operates across a wide-input-voltage range with complete softswitching
is identified, which switches efficiently at higher frequencies and
high output currents with PCB-integrated magnetics, improving significantly
power density compared to state-of-the-art designs. This topology embeds a
sophisticated PCB-integrated matrix transformer that has a single path for the
magnetic flux, ensuring equal flux linkage of parallel-connected secondary
windings despite possible geometric PCB-layout asymmetries or reluctance
imbalances. The so-called snake-core transformer avoids the emergence of
circulating currents between parallel-connected secondary windings and
guarantees proper operation of parallel-connected, magnetically-coupled
converter modules.
The benefits of the proposed topology, control scheme and transformer design
are validated by three fabricated 300 V-430 V-input, 12 V-output DC/DC
hardware demonstrators. The converters utilize an LLC-based control scheme
for complete soft-switching and the snake-core transformer to divide the output
current with a balanced flux among multiple secondary windings. First,
a 3 kW DC/DC series-resonant converter achieves 350Win3 (21”4 kWdm3)
vii
Abstract
power density and 94 % peak efficiency, validating control and transformer
operation. Then, a second hardware prototype with 1”5 kW showcases a peak
efficiency close to 96 % and a power density of 337Win3 (20”6 kWdm3), with
full PCB-integration and zero-voltage switching even down to zero load. Finally,
the third demonstrator—a magnetically-coupled, input-parallel/outputparallel,
two-1”5 kW-module DC/DC converter—achieves a peak efficiency
of nearly 97 % and a power density of 345Win3 (21”1 kWdm3) with ideal
current sharing among modules and stable operation, important characteristics
enabled by the novel snake-core transformer. Detailed loss models are
derived for every converter’s component and the measurement results are in
excellent agreement with the calculated values. These loss models are used
to identify improvements to further boost efficiency, the most important of
which is the minimization of delay times in synchronous rectification with
either synchronous rectifier ICs embedded into the power-device’s package
or, at a minimum, Kelvin-source connections on high-current MOSFETs.
The results accomplished in this thesis indicate the necessity of careful
topology/control selection and advanced-magnetics design for enabling WBGbased
industrial power supplies that will outperform state-of-the-art solutions
and catapult them to the next-generation performance standards. None of
these features—be it WBG devices, wide-gain-range resonant converters,
or advanced PCB-integrated magnetics—will alone enable next-generation
power-supply modules, but the thoughtful combination of these technologies
and their careful application to the particular application, with emphasis to
high-frequency PCB magnetics and soft-switching topologies, which enable
compact and cost-effective converters with competitive efficiencies.
VIEW FULL THESIS:
domingo, 21 de agosto de 2022
Optimal Design Methodology for A High-Frequency Transformer Using Finite Element Analysis and Machine Learning by Eunchong Noh School of Electrical and Computer Engineering University of Seoul February 2022
Optimal Design Methodology for A High-Frequency Transformer Using Finite Element Analysis and Machine Learning
A thesis submitted in partial fulfillment of
the requirements for the degree of
Master of Science
(Electrical and Computer Engineering)
December 2021
Thesis committee:
Gyu-Sik Kim, Professor, ECE, University of Seoul
Seung-Hwan Lee, Associate Professor, ECE. University of Seoul
Moon-Que Lee, Professor, ECE, University of Seoul
Abstract
The demand for isolated DC-DC converters is increasing due to the spread of
electric vehicles (EV) and the expansion of renewable energy use. Accordingly, the
need for a high-frequency transformer, a key component of an isolated DC-DC
converter, is also increasing. This trend is also taking place in the field of railway
locomotive systems. Solid state transformer (SST) technology to improve the
performance and efficiency of railway locomotive propulsion systems is being
actively researched, and high-frequency transformer is the core of SST. Highfrequency
transformer design for railway locomotive systems has more complex
design elements that must be considered for volume-loss optimization and
insulation and thermal design.
This thesis investigates an optimization design methodology using machine
learning and NSGA-II for optimized high-frequency transformer design. For
machine learning, Finite-element analysis (FEA) simulation was used to obtain
high-frequency transformer parameter data. Conventional high-frequency
transformer optimization design methods used analytical models for parameter
calculation. However, this analytical model has a significant error when the shape
of the high-frequency transformer becomes complicated. In particular, the leakage
inductance of the high-frequency transformer is difficult to calculate with an
analytical model. So, it is difficult and cumbersome to apply it in the design. This
thesis obtained magnetizing inductance, leakage inductance, and copper loss of
shell-type transformer models in various shapes using FEA simulation. Then, using
the data obtained from the FEA simulation, a machine learning regression model
was created to minimize the parameter calculation error in complex shapes. In
addition, the NSGA-II algorithm, which is widely used in multi-variable
optimization design, is used to find the optimal transformer shape to perform
optimization that can satisfy multiple design elements at the same time.
Each parameter inferred by the machine learning regression model showed a
high correlation and sufficiently low inference error rate, used for parameter
calculation in the NSGA-II algorithm. The inferred parameters are used to calculate
transformer loss for optimization design or check whether constraints are satisfied.
Through the optimization design using NSGA-II, a Pareto front curve for volume
and loss that satisfies all design conditions was obtained. The designer can select
and use the designs according to the situation.
The methodology can be designed for more complex shapes to achieve higherperformance
high-frequency transformer design. In addition, the complexity of the
design is reduced because numerous consideration factors can be easily considered
through constraint setting in the NSGA-II. Finally, unlike the conventional design
methodology, which has a significant influence on the skill and intuition of the
designer, once the environment is set up, the design proceeds only by inputting
target parameters and executing the code so that the design time can be reduced.
Therefore, it is possible to design a high-frequency transformer with constantly
high performance regardless of the designer's skill level.
Assinar:
Postagens (Atom)
JOSIL ARTISTA PLASTICO FORTALEZA CEARA BRASIL AV.HERACLITO GRAÇA 41 TEL(85)32542378
