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Fecha Publicación: 2023-08-01T14:29:00.003-07:00


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.


Fecha Publicación: 2023-08-01T07:06:00.003-07:00


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


Fecha Publicación: 2023-07-28T07:11:00.002-07:00

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. 

Fecha Publicación: 2023-07-28T06:54:00.005-07:00

 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 
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.

Fecha Publicación: 2023-07-10T17:16:00.005-07:00

 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.

Fecha Publicación: 2023-06-05T10:35:00.009-07:00


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

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.

Fecha Publicación: 2023-06-05T07:09:00.007-07:00

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 

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.

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.


Fecha Publicación: 2023-06-03T15:59:00.005-07:00

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.

Fecha Publicación: 2023-06-03T15:23:00.005-07:00

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


Fecha Publicación: 2023-04-22T06:22:00.005-07:00

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.

Fecha Publicación: 2023-04-17T06:43:00.005-07:00

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 

 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. 



Fecha Publicación: 2023-04-13T18:46:00.002-07:00

 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.

Fecha Publicación: 2023-04-11T16:43:00.003-07:00


Fecha Publicación: 2023-03-24T15:58:00.001-07:00

 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


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.

VIEW FULL TEXT: https://www.mediafire.com/file/l8fv816xqzvk8eq/Relatório+-+ANALYSIS+AND+DESIGN+OF+A+FORWARD+CONVERTER+(1).pdf/file

Fecha Publicación: 2023-03-24T07:44:00.011-07:00

                                                    FIGURA 1


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.

Fecha Publicación: 2023-03-19T16:48:00.005-07:00

Fecha Publicación: 2023-02-27T16:53:00.003-08:00

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 

 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.

Fecha Publicación: 2022-12-31T16:52:00.002-08:00
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


 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.

Fecha Publicación: 2022-12-28T02:19:00.002-08:00


Fecha Publicación: 2022-12-03T10:42:00.003-08:00

 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 

 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.

Fecha Publicación: 2022-12-02T06:29:00.004-08:00



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.


Fecha Publicación: 2022-11-22T10:28:00.005-08:00

 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.


Fecha Publicación: 2022-11-18T11:01:00.003-08:00


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
 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 %.

Fecha Publicación: 2022-10-14T09:03:00.003-07:00


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

Fecha Publicación: 2022-10-10T18:39:00.003-07:00

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

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!