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ABSTRACT
Presently, the specific gravity of the used field of the AC-AC phase control converter in which the effective value and frequency have got the output of the other alternating current by approving the alternating current used for the motoring and dimming circuit, and etc. As the development of the dimming circuit, controlling the brightness of the illumination by the expansion of the illumination industry market using LED along with the development of the various product using the electric motor including an air-conditioner, refrigerator, washing machine, and etc. Due to the development of an industry as the driving source and etc. Increases. In using the power offset required in the device connected to the output terminal to the object using the phase control, it is due to be convenient.
The AC-AC phase control converter uses in order to set the power offset of the load in which the part of the input voltage waveform is not delivered to the load and while a switching occurs for every cycle of the alternating current, that is the input voltage, requiring the power offset which is lower than the input electrode value by lowering the effective value of the output voltage and output current and the power offset taking the load.
In this paper, PSIM program and PSpice program were used. PSIM program is the program which it simulates by using the ideal element. PSpice program is the program which selects and can simulate the actually used device
By using the single phase control converter and three phase control converter (Y-Y wiring) and three phase control converter (Y-∆ wiring) PSIM program and PSpice program among the AC-AC phase control converter among the simulation program, this paper enforced a simulation and inquired into the difference of two programs.
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Switch Mode Power Supply Topologies, a Comparative Study
Khoo Ghim Wee
School of Science and Technology
A thesis submitted to SIM University in partial fulfillment of the requirements for the degree of Bachelor of Engineering
2009
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Resonance based zero-voltage zero-current switching
full bridge converter
Rouhollah Karimi, Ehsan Adib, Hosein Farzanehfard
Department of Electrical and Computer Engineering, Isfahan University of Technology, Iran
E-mail: r.karimi@ec.iut.ac.ir
Abstract: A zero-voltage and zero-current switching full bridge converter with series resonance tank is presented in this study.
This converter is based on standard full bridge topology and a series capacitor is added in the primary side to reset the leakage
inductance current without any additional auxiliary circuit. Leakage inductance of the transformer is used as the resonance
inductance. Using series resonance tank and applying control pulses with fix frequency, zero-voltage switching for leading
leg and zero-current switching for lagging leg is achieved. The output power is controlled using phase shift technique. In the
proposed converter, soft-switching condition is attained for wide range of load variation. Due to its high performance and
minimum additional components with respect to regular converter, this converter can be applied for medium to high-power
applications. Topology and operating modes are discussed and the validity of theoretical analysis is verified by prototype
experimental results.
Space High-Voltage Power Module Wenjie Zhao1*, Yuanyuan Jiang1, Jianchao Wu2, Yonghui Huang1, Yan Zhu1, Junshe An1 and Cheng-an Wan2 1 National Space Science Center, The Chinese Academy of Sciences, Beijing, China, 2 China Aerospace Science and Technology Corporation, Beijing, China Space High-Voltage Power Module Wenjie Zhao1*, Yuanyuan Jiang1, Jianchao Wu2, Yonghui Huang1, Yan Zhu1, Junshe An1 and Cheng-an Wan2
1 National Space Science Center, The Chinese Academy of Sciences, Beijing, China, 2 China Aerospace Science
and Technology Corporation, Beijing, China ABSTRACT
With the rapid development of the world’s aerospace technologies, a high-power
and high-reliability space high-voltage power supply is significantly required by new
generation of applications, including high-power electric propulsion, space welding,
deep space exploration, and space solar power stations. However, it is quite difficult
for space power supplies to directly achieve high-voltage output from the bus, because
of the harshness of the space environment and the performance limitations of existing
aerospace-grade electronic components. This paper proposes a high-voltage power
supply module design for space welding applications, which outputs 1 kV and
200 W when the input is 100 V. This paper also improves the efficiency of the high-
voltage converter with a phase-shifted full-bridge series resonant circuit, then simulates
the optimized power module and the electric field distribution of the high-voltage
circuit board.
Magnetics design is often the most overlooked aspect of the design of power electronic converters. This is episode 9 of our 'Powerful Knowledge' series and we go into some depths of how to approach magnetics design using energy storage as a starting point with an example of a mains input 50W flyback converter running at 100kHz switching frequency.
We cover aspects such as winding structure, basic core loss modelling, impacting of fringing fields near the airgap and practical characterization.
급속충전기용 파워 모듈을 위한 단일단 AC-DC 컨버터
레덧탕1
, 최세완✝
A Single-Stage AC-DC Power Module Converter for Fast-Charger
Tat-Thang LE and Sewan Choi
The Transactions of the Korean Institute of Power Electronics, Vol. 27, No. 5, October 2022
Abstract
In this study, a single-stage, four-phase, interleaved, totem-pole AC-DC converter is proposed for a
super-fast charger station that requires high power, a wide voltage range, and bidirectional operation
capabilities and adopts various types of electric transport vehicles. The proposed topology is based on
current-fed push-pull dual active bridge converter combined with the totem-pole operation. Owing to the
four-phase interleaving effect, the bridge on the grid side can switch at 0.25, 0.5, and 0.75 to achieve a
ripple-free grid current. The input filter can be removed theoretically. Switching methods for the duty of the
secondary-side duty cycle are proposed, and they correspond to the primary duty cycle for reducing the
circulating power and handling the total harmonic distortion. Therefore, the converter can operate under a wide
voltage range. Experimental results from a 7.5 kW prototype are used to validate the proposed concept.
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3.3kW Bidirectional OBC Design with Active Clamp Flyback Converter
Hyeok-Min Kwon, So-Jeong Kong, Jae-Hyuck Choi, Dae-Young Hong and Jun-Young Lee†
Myongji University Electrical Engineering
액티브 클램프 플라이백 컨버터를 이용한 3.3kW 양방향 OBC 설계
권혁민, 공소정, 최재혁, 홍대영, 이준영†
명지대학교 전기공학과
ABSTRACT
본 논문은 3.3kW급 OBC에 사용되는 DC-DC 양방향
Flyback 컨버터를 제안한다. 기존 Flyback 컨버터에서 보조 스
위치를 사용한 회로를 적용하여 변압기 누설 값에 저장된 에너
지를 재활용하여 메인 스위치 전압 스파이크를 최소화하는 방
식을 사용했고 이를 대칭구조로 적용하였다. 모든 전력반도체
소자는 SiC-MOSFET을 적용하였다. 스위칭 주파수 70kHz 조
건에서 입력전압은 400V이며 배터리 전압 100V, 250V, 330V,
450V 네 구간에서 정상 동작을 확인하였으며 정방향 최대 효
율:97.58%, 역방향 최대 효율 97.48%를 달성하였다.
ABSTRACT
This paper proposes a DC-DC bi-directional flyback converter used in a 3.3kW xclass OBC. In the existing flyback converter, a circuit using an auxiliary switch was applied to recycle the energy stored in the transformer leakage value to minimize the main switch voltage spike, and this was applied in a symmetrical structure. All power semiconductor devices applied SiC-MOSFETs. Under the condition of the switching frequency of 70kHz, the input voltage was 400V, and normal operation was confirmed in four sections of battery voltage 100V, 250V, 330V, and 450V, and the maximum forward efficiency: 97.58% and the maximum reverse efficiency 97.48% were achieved.
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Three-Phase Single-Stage Bidirectional CCM
Soft-Switching AC–DC Converter With
Minimum Switch Count
Jaeyeon Lee , Hyeonju Jeong, Tat-Thang LE , Member, IEEE, and Sewan Choi , Fellow, IEEE
Abstract—In this article, a three-phase single-stage bidirectional
ac–dc converter with low component count is proposed.
The single-stage structure is configured by integrating a threephase
ac–dc converter and a three-phase dual active bridge converter.
The power factor correction and bidirectional power control
are performed by adjusting the modulation index of sinusoidal
pulse width modulation (SPWM) and phase-shift angle
between the primary and secondary bridges. The lowfrequency
components generated by SPWM are absorbed by
fundamental blocking capacitors connected in series with transformer
windings, resulting in true high-frequency isolation. The
proposed converter can achieve soft-switching of all switching
devices even in continuous conduction mode. A 110 Vac, 3 kW, 100
kHz prototype is implemented to validate the proposed concept and
demonstrated 95.34% peak efficiency.
Compact Integrated Transformer – Grid Inductor Structure for E-Capless Single-Stage EV Charger Ramadhan Muhammad Hakim, Huu-Phuc Kieu, Junyeong Park, Tat-Thang LE, Member, IEEE, Sewan Choi, Fellow, IEEE, Byeongseob Song, Hoyoung Jung, and Bokyung Yoon Compact Integrated Transformer – Grid Inductor Structure for E-Capless Single-Stage EV Charger
Ramadhan Muhammad Hakim, Huu-Phuc Kieu, Junyeong Park, Tat-Thang LE, Member, IEEE,
Sewan Choi, Fellow, IEEE, Byeongseob Song, Hoyoung Jung, and Bokyung Yoon
Abstract—This paper proposes a planar magnetic integration technique that combines the grid inductors and transformer in the single-stage E-capless EV charger into one core. The proposed integration technique reduces the number of magnetic components; therefore, the cost, total magnetic core loss, and volume can be significantly reduced. Using the integrated structure, the overall converter power density increases up to 11.1% compared to the non-integrated one. This paper also presents a detailed analysis of the optimal PCB winding arrangement considering both AC resistance and winding stray capacitance. Due to the high DC resistance of PCB winding, Litz wire was also considered for the proposed integrated structure. The effectiveness of the proposed structure was validated by implementing it on a 3.7 kW prototype of a single-stage AC-DC converter. Results show that the prototype with the proposed integrated structure achieved higher efficiency with both PCB winding and Litz wire. Peak efficiency of 97.17% and 6.55 kW/L power density were achieved.
Index Terms—Planar cores, Electric vehicles, Battery chargers, AC-DC power converters
WEB SITE ORIGINAL EN LA INTERNET:
High voltage insulation design of coreless, planar PCB transformers for multi-MHz power supplies Ole Christian Spro, Student Member, IEEE, Frank Mauseth, Member, IEEE---Department of Electric Power Engineering, Norwegian University of Science and Technology, Trondheim, Norway, Dimosthenis Peftitsis,
High voltage insulation design of coreless, planar
PCB transformers for multi-MHz power supplies
Ole Christian Spro, Student Member, IEEE, Frank Mauseth, Member, IEEE,
Dimosthenis Peftitsis, Senior Member, IEEE,
Abstract—This paper investigates the insulation design for
printed, planar, coreless, and high-frequency transformers with
high isolation-voltage. By using finite element analysis on 2D
axial-symmetry, the transformer circuit parameters and electric
field distribution are modelled and estimated. Several transformers
are designed for an operating frequency of 6.78 MHz. The
high frequency, coreless design allows for using thicker insulation
material while ensuring a high transformer efficiency. The
inclusion of the coupling capacitance in the design optimisation
results in several design solutions with the same figure of merit,
but with different footprint and isolation voltages. Moreover,
high electric fields are identified around the sharp edges of the
PCB windings. Finally, the electrical and isolation performance
is verified experimentally. The measured electrical properties
are close to the simulated values, validating the chosen model.
Breakdown tests demonstrate the feasibility of isolation voltage
levels up to several tens of kilovolts. The majority of breakdowns
occurs at the outer edge of the PCB winding that was identified as
a high-field area. Additionally, a concept for grading the electric
field of PCB windings is also proposed. Based on the results, the
design aspects are discussed in detail for planar, high-frequency
isolation transformers with medium-voltage isolation level.
A Study on the Explosion and Fire Risk
of the Lithium Battery
Sang-BoSim
Department of Fire and Disaster Prevention Engineering,
The graduate School Hoseo University-Asan,Korea
ABSTRACT
Due to recent development of IT technology, information level of Korea is said to be the world-best. Thus mobile devices such as cell phones, notebook, and tablet PC that could be used without limitations are trending. Along the trend, high energy high density secondary batteries used as the power source for portable devices are also in the spotlight, and among them Lithium battery demand is rising. Generally a Lithium battery should be certified with KS C 8541 (Lithium secondary battery rule) in order to be on the market. However, battery accidents are growing in number and people are raising questions about the safety of the batteries.
Certified Lithium battery’s safety is guaranteed within normal state, but at abnormal states such as damage to protective circuit, the danger rises due to elimination of minimum protection. Recent studies regarding Lithium batteries only measured ignition status for flammable gas, but did not provide detailed analysis. Also, risk analysis according to battery capacity and comparative analysis between the two representative batteries, Lithium Polymer battery and Lithium Ion battery are rarely carried out. Also, research about general danger of Lithium batteries such as ignition at high temperature environment is incomplete.
This study selected five types of Li-Polymer batteries and three types of Li-Ion batteries of different capacity in order to analyze ignition and fire danger according to usage environment. The results are as following.
1. We designed an ignition circuit using IEC type spark ignition test apparatus based on KS C IEC 60079-11 standard in order to measure the explosion hazard of Lithium battery spark discharge. Through measuring the ignition limit of methane, propane, ethylene, and helium, the result showed that gas with higher danger showed more explosion to less number of battery connection. Also, batteries with not Protection Circuit Module (PCM) exploded more often during connection with battery compared with batteries that had protection circuits.
2. An experiment was conduction using a pyrostat based on UL 1642 and KS C 8541 standard in order to measure Lithium battery’s explosion danger at high temperature environment. As the result, Li-Polymer batter with pack type external material had higher risk of explosion compared to cap type Li-Ion battery. Li-Polymer battery had 160~170℃ explosion between 1970~2700 seconds, and the explosion occurred for the electrolytes seeped out from the cracked battery pack after swelling due to evaporation. On the other hand, Li-Ion battery had 176~197℃ explosion between 3000~3800 seconds caused by vaporized electrolyte increasing the pressure within the battery and protruding to the vulnerable positive (+) end.
3. Short circuit was designed in order to measure the temperature increase according to the short circuit current. For batteries with protection circuit, there was no temperature change caused by short circuit current due to current limitation. However, for batteries with no protection circuit, 30.7~35.6A of maximum short circuit current was produced. For Li-Polymer battery, the current fell until 3.9~12.7A after the maximum short circuit current, but increased again to 5.5~17.8A, showing two-step curve pattern. The maximum temperature was 125℃. For Li-Ion battery, the maximum short circuit current fell steeply to 1.3A and decreased steadily, showing a single step curve pattern. It is because the PTC thermistor embed inside limited the flowing current. The maximum temperature was 95℃.
Thus in order to minimize the danger of Lithium battery explosion, the Lithium battery connection number and discharge characteristics should be considered when used at environment with flammable gas. And swelling and explosive characteristics should be considered when using Li-Polymer and Li-Ion batteries at high temperature environment. Also, to prevent hazards caused by mistakes and abnormal statues, a dual safety device of protection circuits are recommended.
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Abstract Electrified vehicles on the market today all use the xclassical two-level inverter as the propulsion inverter. This thesis analyse the potential of using
a cascaded H-bridge multilevel inverter as the propulsion inverter. With a
multilevel inverter, the battery is divided into several parts and the inverter
can now create voltages in smaller voltage levels than the two-level inverter.
This, among other benefits, reduces the EMI spectrum in the phase cables
to the electric machine. It is also shown that these H-bridges can be placed
into the battery casing with a marginal size increase, and some addition of
the cooling circuit performance. The benefit is that the separate inverter can
be omitted.
In this thesis, measurements and parameterisations of the battery cells
are performed at the current and frequency levels that are present in a multilevel inverter drive system. The derived model shows a great match to the
measurements for different operating points and frequencies.
Further, full drive cycle simulations are performed for the two analysed
systems. It is shown that the inverter loss is greatly reduced with the multilevel inverter topology, mainly due to the possibility to use MOSFETs instead
of IGBTs. However, the battery packs in a multilevel inverter experience a
current far from DC when creating the AC-voltages to the electric machine.
This leads to an increase of the battery loss but looking at the total inverterbattery losses, the system shows an efficiency improvement over the xclassical
two-level system for all but one drive cycle. In the NEDC drive cycle the
losses are reduced by 30 % but in the demanding US06 drive cycle the losses
are increased by 11 % due to the high reactive power demand at high speed
driving. These figures are valid for a plug-in hybrid with a 50 km electrical
range where no filter capacitors are used. In a pure electric vehicle, there is
always an energy benefit of using a multilevel converter since a larger battery
will have lower losses. By placing capacitors over the inputs of the H-bridges,
the battery current is filtered. Two different capacitor chemistries are analysed and experimentally verified and an improvement is shown, even for a
small amount of capacitors and especially at cold operating conditions.
Analysis and design of a Forward Converter. Students : EV2. C. Arboy et B. Cousin, EN 2006
Type of report : Rapport de Projet de Fin d’Etude (PFE)
University : Federal University of Santa Catarina (UFSC)
Power Electronic Engineering Department (INEP)
Project chief : Ivo Barbi, Professor in Power Electronics Institute at the UFSC
ABSTRACT
Our project consists in the study, the design and the realization of a Forward converter.
The design of a forward converter demands great precision when calculating the different
parameters and restrictions that will have to be applied when conceiving the model.
The first step was the understanding of the forward converter in order to know the main
parameters needed and the different mathematical equations for the choice of the different
components of the forward. The use of the software PSIM completes this work for the
comprehension,the collection of different values and for the checking of the circuit
calculations.
Once this had been done it was possible to proceed to the construction and to the test the
forward converter in the laboratory. These different tests allowed us to validate the performed
design and simulations.
Then we have controlled the output voltage of the forward converter with a feedback
control circuit in order to assure the optimal function of the forward and automatic control of
the different parameters.
RESUME
Ce projet a pour but l’étude et la réalisation complète d’un convertisseur Forward
s’inscrivant dans un cahier des charges bien précis afin d’être tester.
Un travail préliminaire portant sur l’étude qualitatives du convertisseur permet de dégager
les nombreux paramètres qu’il sera nécessaire de surveiller ainsi que d’obtenir les différentes
équations mathématiques utiles pour dimensionner les éléments constitutif du convertisseur.
La simulation par outil informatique vient compléter cette démarche amont et nous aide
ainsi à accéder à des résultats qu’il convient de confronter une fois le prototype réaliser.
Ensuite le convertisseur une fois dimensionner, en ayant respecté au maximum le cahier
des charges est construit puis testé. Ces différents tests nous permettent de valider notre
convertisseur et les simulations effectuées.
Enfin l’intégration dans une chaine de contrôle permet d’asservir le convertisseur tout en
assurant un fonctionnement optimal de ce dernier et le contrôle des différents paramètres.
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FIGURA 1
CONVERSOR PUSH-PULL ALIMENTADO EM CORRENTE-CURRENT-FED PUSH PULL CONVERTER
A Figura 1 mostra o conversor push pull alimentado em
corrente, onde o comando das chaves ´e realizado com frequencia
de chaveamento constante e razâo ciclica variavel. O conversor
opera em modo de condução contınua, onde a tensâo de entrada
CC em conjunto com o indutor de entrada formam uma fonte de
corrente.
REPORTAJE DE RTV DE LA UNIVERSIDAD NACIONAL MAYOR DE SAN MARCOS -FACULTAD DE INGENIERIA ELECTRONICA sobre la historia de Aldair Escobar Gutiérrez, el capitán de Selección de Taekwondo UNMSM-INGENIERIA ELECTRONICA-LIMA-PERU.
Robust Control of a Multi-phase Interleaved Boost Converter for
Photovoltaic Application using μ-Synthesis Approach A dissertation submitted in partial fulfillment
of the requirements for the degree of
Doctor of Philosophy in Engineering with a concentration in Electrical Engineering
by
Badur Mueedh Alharbi University of Arkansas
Master of Science in Electrical Engineering, 2020
December 2020
University of Arkansas
ABSTRACT
The high demand of energy efficiency has led to the development power converter
topologies and control system designs within the field of power electronics. Recent advances of
interleaved boost converters have showed improved features between the power conversion
topologies in several aspects, including power quality, efficiency, sustainability and reliability.
Interleaved boost converter with multi-phase technique for PV system is an attractive area
for distributed power generation. During load variation or power supply changes due to the weather
changes the output voltage requires a robust control to maintain stable and perform robustness.
Connecting converters in series and parallel have the advantages of modularity, scalability,
reliability, distributed location of capacitors which make it favorable in industrial applications. In
this dissertation, a design of μ-synthesis controller is proposed to address the design specification
of multi-phase interleaved boost converter at several power applications. This thesis contributes to
the ongoing research on the IBC topology by proposing the modeling, applications uses and control
techniques to the stability challenges. The research proposes a new strategy of robust control
applied to a non-isolated DC/DC interleaved boost converter with a high step voltage ratio as
multi-phase, multi-stage which is favorable for PV applications. The proposed controller is
designed based on μ-synthesis technique to approach a high regulated output voltage, better
efficiency, gain a fast regulation response against disturbance and load variation with a better
dynamic performance and achieve robustness. The controller has been simulated using
MATLAB/Simulink software and validated through experimental results which show the
effectiveness and the robustness.
태양전지 및 연료전지용 소용량
하이브리드 인버터 설계 및 구현
Design and Implementation of Hybrid Small-Sized
Power Inverter for PV and Fuel Cell
指導敎授崔宙燁
이 論文을 工學博士學位請求論文으로 提出함
Design and implementation of small-capacity hybrid inverters for solar cells and fuel cells
Author
Jo Sang-yoon
Seoul: Kwangwoon University Graduate School, 2019
Dissertation
Thesis (Doctoral)-- Kwangwoon University Graduate School: Department of Electrical Engineering 2019.2
Year of issue
2019
2018年12月7日
ABSTRACT
Design and Implementation of Hybrid
Small-Sized Power Inverter for PV and Fuel Cell
As a major source of power for robots and drones that emerged as key
elements of the Fourth Industrial Revolution era, solar cells, fuel cells, and
lithium-ion batteries are receiving spotlight as batteries that can produce
high power for long periods of time. Especially, the global market for solar
cells and fuel cells is expanding as new and renewable energy sources.
While inverter demand is essential for efficient operation of batteries and
studies of high-quality inverter technologies such as solar energy, energy
storage devices such as robots, drones, etc. As hybrid technologies that
supplement solar energy and fuel cells in battery power are
commercialized in the U.S., including Japan, it is imperative to study new
power converters and control technologies that add green power to
secondary batteries.
The purpose of this paper is to design and implement a small-capacity
hybrid inverter system for solar cells and fuel cells that efficiently operate
robots and controllers, communications and various mission equipment by
merging solar cells, fuel cells and lithium-ion batteries. To this end, the
electrical model for solar cells, fuel cells and lithium-ion batteries is first
established and the architecture of the hybrid inverter system is proposed
based on these models. After each component has been designed and
verified, the entire system is verified and finally the proposed smallcapacity
hybrid inverter system is demonstrated by mounting the actual
robot's power system.
This paper proposes the structure and function of hybrid inverter
systems by establishing an electrical equivalent linear model,
understanding the power characteristics of solar cells, fuel cells and
lithium-ion batteries with different principles of energy generation. Each
module proposes a new method of impedance matching maximum power
point tracking control technology that is essential to the design of the
buck converter for solar cells and fuel cells. It also designs an interleaved,
bidirectional DC-DC converter with a high-passing ratio for optimal
charging of lithium-ion batteries and proposes an efficiency analysis
method in the multiplier mode. In addition, it proposes a two-way DC-DC
converter that simultaneously takes into account efficiency and stability.
The proposed hybrid inverter system is implemented as a small-capacity
hybrid interver system for solar cells and fuel-cells by proving its
effectiveness through simulation and practical experiments at the module
and system level and by applying it to actual mobile robots.
In conclusion, the research proposed a small hybrid inverter system for
solar cells and fuel cells provides power conversion solutions suitable for
robots, drones, wearable devices, and mobile electronics. Futhermore,
Combined with other energy storage devices other than lithium-ion
batteries, it is also able to be applied as a power converter for large
capacity ESS. Therefore, it presents the possibility of independent
products as modules and system technologies for low-cost, long-term, and
high-power inverter technologies in the future renewable energy sector.
Dissertation for the degree of Doctor of Philosophy
Self-powered Sensor Monitoring System in
Industrial Internet of Things using Off-resonance
Piezoelectric Energy Harvesting Techniques
by Jae Yong Cho
Graduate School of Hanyang University
February 2019
Department of Electrical Engineering
Graduate School of Hanyang University
ABSTRACT
The main keyword in the era of the fourth industrial revolution is IIoT (Industrial
Internet of Things) that enables the interactive network between devices, vehicles, home
appliances, and other items embedded with electronics, software, sensors, actuators and etc.
To realize IIoT world, there are key technologies; sensors, microcontroller, connectivity,
and energy management. Especially, in terms of energy management, many researches
have been carried out about self-powering, a battery-less device from energy harvesting.
At the center, there is piezoelectric energy harvesting technology, which converts
mechanical energy into electrical energy. Lots of researches about piezoelectric energy
harvesting have been carried about because piezoelectric material has relatively high power
density and is easily applicable to various infrastructures like road, building, and factory
close to our daily lives. Ultimately, the goal of this technology is heading for energy saving
and simple installation of sensors used for monitoring structural condition without
inconveniences such as the replacement of the batteries and the complexity of the cables.
In this dissertation, the research about design and fabrication of off-resonance type
piezoelectric energy harvesting systems for IIoT sensor was discussed. Because the actual
frequency environment in a real field is not geared to resonant frequencies, previous
piezoelectric energy harvesting systems were difficult to harvest ambient energy efficiently.
We developed the techniques for harvesting energy efficiently through new structures of
off-resonance piezoelectric energy harvesters according to various frequency environment.
As the final step, the demonstration study was conducted to illustrate IIoT platform as V2I
(Vehicle to Infrastructure) system from the piezoelectric energy harvesting techniques. The
developed harvester was fabricated and installed on the highway (Yeoju-si, Gyeonggi-do,
South Korea). As a result, self-powered temperature sensor monitoring system was
constructed using the energy harvester to be able to operate wireless temperature sensor
(eZ430-RF2500, Texas Instruments, USA) without battery. Finally, the system was
established to inform a driver of the freezing condition on the road in advance as V2I
system.
First, the design and fabrication of the resonance dependent type energy harvester
were conducted. We have developed the piezoelectric energy harvester using wind that is
dependent on the resonant frequency, which is a key component of piezoelectric power
generation. The experiment result showed that the difference in power generation
characteristics when and when not at resonant frequencies makes difficult for the energy
harvester to be applied to actual industrial environments where frequencies vary. Finally, it
is essential to develop energy harvesters considering these diverse frequency environments.
Second, the studies of energy harvesters optimized for different types of frequency
environments in industries were conducted. The frequency environment was divided in four
conditions (single frequency, multi frequency, random frequency, and intermittent
frequency). For single, multi and random frequency conditions, a magneto-mechanical
system was applied as the method of harvesting more energy utilizing magnetic forces. For
an intermittent condition, system design was conducted as the method to overcome the offresonance
region. In single frequency environment, conveyor belts within a smart factory
were presented as an experimental environment and the study was conducted to overcome
an environment using magnets on the core belt that is much lower than the resonant
frequencies of a typical piezoelectric device. In multi frequency environment, water pipes
located in plants or buildings were presented as an experimental environment, and to
harvest more energy, a hybrid system using piezoelectric energy harvester and
electromagnetic energy harvester was studied. In a random frequency environment, the
railway was proposed as experimental condition and the magnetic pendulum energy
harvester utilizing inertial moments was developed. The energy harvester for the
intermittent frequency environment was studied, taking into account the wireless switch
that is sometimes pressed by humans as one of the intermittent frequency environments.
Third, the research was carried out on the energy harvesting circuit, which is essential
for applying the energy harvester to the actual IIoT environment. Preferentially, equivalent
circuit modeling of piezoelectricity and impedance matching study was conducted to
deliver maximum power. The DC-DC converter study was also conducted to convert high
voltage of the piezoelectricity into low voltage so that actual sensor applications can be
self-driven by the energy harvester. Additionally, the research was conducted to create the
desired output voltage, and finally to establish the wireless communication interface.
RESUMO
O presente trabalho apresenta o desenvolvimento de um sistema autônomo de iluminação pública baseado em energia solar fotovolaica e diodos emissores de luz (LEDs). O sistema deve ser capaz de carregar um banco de baterias durante o dia através de um arranjo fotovoltaico e suprir uma carga LED durante a noite. Um conversor bidirecional com transistores de nitreto de gálio (GaN) é utilizado de forma a obter uma estrutura com elevado rendimento e, com isso, otimizar o tamanho do banco de baterias e arranjo fotovoltaico para maximizar a autonomia do sistema ou reduzir os custos de produção, dependendo dos objetivos da aplicação. Foi desenvolvida uma metodologia completa e otimizada para o projeto dos elementos deste sistema autônomo de iluminação. Esta metodologia baseia-se em um algoritmo de busca discreta que avalia um conjunto de componentes disponíveis comercialmente para determinar a melhor combinação de componentes e o melhor ponto de operação do circuito, de modo a minimizar as perdas de energia ao longo do período de operação do sistema. Neste documento é apresentada, inicialmente, uma revisão bibliográfica de aspectos teóricos relacionados aos sistemas autônomos de iluminação, como fonte fotovoltaica, baterias, carga LED, topologias de conversores e soluções comerciais disponíveis. Uma revisão sobre interruptores GaN também é apresentada, abrangendo seu histórico, princípio de funcionamento, características e estado da arte da tecnologia em termos de dispositivos comerciais. Para validar experimentalmente a topologia proposta, um protótipo de 100 W com frequência de comutação arbitrária foi desenvolvido e avaliado. No modo carregador de bateria, o circuito opera em 250 kHz e apresenta eficiências maiores que 92% em toda a faixa de potência com um valor máximo de 97,3%. No modo driver de LED, a frequência de operação escolhida foi de 345 kHz e uma eficiência máxima de 95,8% foi obtida. Para a validação da metodologia de projeto proposta, quatro conversores com potências de 30 W em modo driver e 150 W em modo carregador foram implementados e testados em diferentes pontos de operação. Com isso, comprovou-se que, considerando um conjunto de componentes, a metodologia é capaz de determinar o melhor ponto de operação para maximizar o rendimento, e, considerando diferentes conjuntos de componentes, determinar o melhor em termos de redução da energia perdida, de forma a maximizar a autonomia do sistema.
VER TESE COMPLETA:
(Abstract) This study deals with a new type of inverter called a three-phase SCVD based boost
inverter. The introduced structure is a combination of an SCVD network and the three-phase
bridge to restrict the common-mode voltage. Therefore, the introduced inverter can produce
a high output voltage from the low input voltage. The DC-bus voltage of the introduced
solution stands at twice of the input voltage. Moreover, the variation in common-mode
voltage can o be restricted within one-sixth of DC-bus voltage. Modeling, circuit analysis,
operating principles, and a comparison between the introduced SCVD based boost inverter
with the other VSIs are performed. To confirm the performance improvements of the
introduced SCVD based boost inverter, a preliminary prototype of the introduced SCVD
based boost inverter is built in the laboratory and the simulation studies based on PLECS
environment and experimental studies are performed. Besides that, a modified SCVD based
boost inverter is also introduced to step up the DC-bus voltage to triple of input voltage
instead of twice of input voltage like that in the proposed SCVD based boost inverter.
Furthermore, a common-mode voltage of the modified SCVD based boost inverter is
x
canceled through switching the four extra active-switches based on the Boolean logic
function. As a result, common-mode voltage is maintained as constant at the value of 0 V
during all time. Moreover, the voltage stress across additional semiconductor devices is
standing at one-third of DC-bus voltage. The simulation studies based on PLECS
environment prove the effectiveness of the modified SCVD based boost inverter. Finally, to
validate the performance, operating principle, and feasibility of the modified SCVD based
boost inverter, the experimental studies based on the laboratory prototype with a DSP
F280049C are carried out.
Doctoral Dissertation
A Three-Phase SCVD Based Boost Inverter with
Low Common Mode Voltage for Transformerless
Photovoltaic Grid-Connected System
Department of Electrical Engineering
Graduate School, Chonnam National University
BY Tran Tan Tai
(Abstract)
This study deals with a new type of inverter called a three-phase SCVD based boost
inverter. The introduced structure is a combination of an SCVD network and the three-phase
bridge to restrict the common-mode voltage. Therefore, the introduced inverter can produce
a high output voltage from the low input voltage. The DC-bus voltage of the introduced
solution stands at twice of the input voltage. Moreover, the variation in common-mode
voltage can o be restricted within one-sixth of DC-bus voltage. Modeling, circuit analysis,
operating principles, and a comparison between the introduced SCVD based boost inverter
with the other VSIs are performed. To confirm the performance improvements of the
introduced SCVD based boost inverter, a preliminary prototype of the introduced SCVD
based boost inverter is built in the laboratory and the simulation studies based on PLECS
environment and experimental studies are performed. Besides that, a modified SCVD based
boost inverter is also introduced to step up the DC-bus voltage to triple of input voltage
instead of twice of input voltage like that in the proposed SCVD based boost inverter.
Furthermore, a common-mode voltage of the modified SCVD based boost inverter is
canceled through switching the four extra active-switches based on the Boolean logic
function. As a result, common-mode voltage is maintained as constant at the value of 0 V
during all time. Moreover, the voltage stress across additional semiconductor devices is
standing at one-third of DC-bus voltage. The simulation studies based on PLECS
environment prove the effectiveness of the modified SCVD based boost inverter. Finally, to
validate the performance, operating principle, and feasibility of the modified SCVD based
boost inverter, the experimental studies based on the laboratory prototype with a DSP
F280049C are carried out.
VIEW FULL DOCTORAL DISSERTATION:
LINK ALTERNATIVO DOCTORAL DISSERTATION:
A Study on the High Efficiency Inverter for Driving an
Induction Motor using GaN MOSFET
Park, Sang-yong
Dept. of Electronic Engineering
The Graduate School
Hanyang University
ABSTRACT
It was proved in this paper that the efficiency of the inverter using GaN
MOSFET ,which is regarded as a next generation power semiconductor,
was much improved comparing the efficiency to the counterpart using the
conventional Si MOSFET. Comparing the characteristics of GaN MOSFET
to those of Si MOSFET, GaN MOSFET shows very low on resistance and
very fast switching speed due to the high breakdown voltage and very
small parasitic capacitances. Therefore, using GaN MOSFET as switching
devices of the inverter, it is expected that the efficiency and characteristics
of the inverter can be improved since the switching and conduction losses
and switching noise can be reduced.
In this paper, to demonstrate the superiority of GaN MOSFET to Si
MOSFET, the inverter using GaN MOSFET for driving a 2.2 kW induction
motor was fabricated. The design specification of the inverter fabricated is
as follows: input voltage is 220 Vac, switching frequency is 20 kHz, and
the operating frequency is 0 to 70 Hz. The fabricated inverter was tested
and the normal operation of the inverter was confirmed. Finally the
efficiency of the inverter was measured and the results of measured
efficiency was compared to those of Si MOSFET inverter with the same
specification as the GaN MOSFET inverter fabricated. From the
comparison results, it is known that the efficiency of the GaN MOSFET
inverter is superior to that of Si MOSFET inverter at the full range of
load. The maximum efficiency of the GaN MOSFET inverter was
measured as 98.41 %.
VIEW FULL TEXT:
1.2 Objetivos de la tesis
.
La red eléctrica es de naturaleza alterna, con lo que si se quiere inyectar energía en la red se debe de hacer mediante corriente alterna. Sin embargo, la corriente proporcionada por un generador fotovoltaico es de naturaleza continua. Es por ello que se hace necesaria la utilización de una etapa de conversión electrónica DC/AC, denominada inversor. En las instalaciones fotovoltaicas de conexión a red se utilizan tanto inversores trifásicos, que inyectan la potencia generada a una red trifásica, como inversores monofásicos que la inyectan a una fase. Normalmente, en instalaciones de potencias
inferiores a 4.6-6kW4, se utilizan inversores monofásicos. En instalaciones de más potencia, tanto domésticas como grandes plantas, se utilizan inversores trifásicos.
Esta tesis se va a centrar en los inversores fotovoltaicos de conexión a red utilizados en grandes plantas de generación eléctrica. Tal y como se ha apuntado anteriormente, estas instalaciones tienen una potencia de entre 1MW y los 247MW de la instalación más grande del mundo a día de hoy. Se suelen ubicar en lugares con una alta irradiación, aprovechando terrenos de escaso valor urbanístico o para la agricultura. El factor económico es, por lo tanto, el principal parámetros a tener en cuenta en el diseño de este tipo de instalaciones ya que se busca la mayor rentabilidad. Así, los costes de todos los elementos que componen la instalación, incluido el inversor, tienen que ser lo menor posibles. El coste del inversor en relación a la potencia del mismo, ratio €/Vat, suele ser mejor en los inversores de mayor potencia y es por ello que, en este tipo de instalaciones en las que se busca una etapa de conversión lo más económica posible, se utilizan los mayores inversores del mercado con potencias de entre 500kW y 1MW, en lugar de una cantidad mayor de inversores de menor potencia. Es precisamente el diseño de estos inversores de gran potencia el objetivo principal de esta tesis.
Cabe destacar que el hecho de que se busque la instalación más económica posible no siempre va ligado a que el inversor tenga que ser lo más barato posible. Lo importante es conseguir la mayor rentabilidad de la totalidad de la instalación, y eso requiere en ocasiones encarecer ligeramente el inversor si con ello se mejoran ciertas prestaciones del mismo que finalmente desembocan en el abaratamiento de otro elemento de la instalación, o en el aumento de la productividad de la misma.
El factor más importante que hace que las características de un inversor difieran de las de otros, es la arquitectura utilizada en cada uno de ellos. En estos inversores fotovoltaicos de alta potencia existen tres topologías principales. La primera de ellas es el Inversor Centralizado (IC). Se trata de una etapa de conversión única por la cual circula la totalidad de la potencia inyectada a la red. Por un lado entra la potencia proveniente del campo solar, que es de carácter continuo. El inversor convierte la potencia en forma alterna para poder inyectarla a la red eléctrica que es también de carácter alterno. La red eléctrica a la que se conectan este tipo de inversores de gran potencia es de tipo IT, con el neutro aislado de tierra.
VER LA TESIS COMPLETA: https://academica-e.unavarra.es/xmlui/bitstream/2454/29278/1/04%20Tesis%20doctoral%20Mikel%20Borrega%20Ayala.pdf
Analysis, Design, and Control of a
Modular Multilevel Series-Parallel
Converter (MMSPC)
Zur Erlangung des akademischen Grades eines
DOKTOR-INGENIEURS
von der KIT-Fakultät für
Elektrotechnik und Informationstechnik
des Karlsruher Instituts für Technologie (KIT)
genehmigte
DISSERTATION
von
M.Eng. Christian Korte
geb. in: Gerolstein
Vorwort
Diese Arbeit entstand während meiner Tätigkeit als wissenschaftlicher Mitarbeiter
am Elektrotechnischen Institut (ETI) des Karlsruher Instituts für Technologie
(KIT). Im Rahmen einer wissenschaftlichen Kooperation hatte ich
die Möglichkeit einen neuartigen Ansatz zur Realisierung des elektrischen
Automobil-Antriebsstrangs zu erforschen.
Dieser Ansatz, der Modular Multilevel Series-Parallel Converter (MMSPC),
zieht eine umfassende Umgestaltung der elektrischen Automobil-Architektur
nach sich. Aus diesem Grund habe ich mir die Aufgabe gesetzt, einen möglichst
fundamentalen wissenschaftlichen Vergleich zwischen dem herkömmlichen Ansatz
und dem MMSPC zu erarbeiten. Ferner habe ich mich darauf konzentriert,
die Leistungsfähigkeit des MMSPC durch Regelung zu erhöhen.
Ohne die durchgehende Unterstützung aus meinem privaten und beruflichen Umfeld
wäre es nicht möglich gewesen, diese Arbeit erfolgreich abzuschließen.
Dafür möchte ich mich bei allen Beteiligten herzlich bedanken.
Insbesondere gilt dieser Dank meinem Doktorvater Prof. Dr.-Ing Marc Hiller, der
es mir ermöglicht hat mit großer wissenschaftlicher Freiheit an meiner Arbeit
zu forschen. Bei Prof. Dr.-Ing Dieter Gerling bedanke ich mich ebenfalls für
die Begutachtung und die Übernahme des Korreferats. Zudem möchte ich mich
bei Prof. Dr.-Ing Malte Jaensch und Prof. Dr.-Ing. Stefan Götz bedanken, für
das entgegengebrachte Vertrauen und die große Unterstützung während meiner
Tätigkeit bei Porsche Engineering.
Ohne die außergewöhnliche Atmosphäre und Kollegialität am ETI wäre die
Entstehung dieser Arbeit mit deutlich weniger Freude und guten Erinnerungen
verbunden. Dafür bedanke ich mich bei allen Kollegen und Studenten des ETI,
mit denen ich das Vergnügen hatte zu Arbeiten.
Mein Dank richtet sich insbesondere an Daniel, für die viele Hilfe bei meinen
Publikationen, dafür dass Du immer die Wissenschaft am ETI vorangetrieben
hast und vor Allem für die ganzen unvergesslichen Erlebnisse die wir geteilt
haben. Weiterhin möchte ich mich bei Firat, Patrick, Simon, Felix, Felix und
Tobi für Eure andauernde Unterstützung und die großartige Zeit bedanken.
Seit meiner Kindheit haben mir meine Eltern und (meistens) meine Schwester
jederzeit den Rückhalt gegeben, den ich benötigte um erfolgreich meine Fortbildung
und meine Promotion zu bestehen. Dafür bedanke ich mich herzlichst,
denn ohne Euch hätte es nicht klappen können.
Während meiner Promotion hat Ravina am meisten miterlebt, wie ich mit der
Arbeit gekämpft habe. Dennoch hast Du mir immer geholfen das Beste aus mir
herauszuholen und immer an meinen Erfolg geglaubt. Danke dafür und dass Du
eine wundervolle Freundin bist!
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