3-phase Dynamic Voltage Restorer with Switching Cell Structured Direct AC-AC Converter Using Interphase Voltage* Hyeongmin Lee School of Electronic and Electrical Engineering Graduate School, Kyungpook National University Daegu, Korea (Supervised by Professor Heung-Geun Kim)

 

3-phase Dynamic Voltage Restorer with Switching Cell Structured Direct AC-AC Converter Using Interphase Voltage* Hyeongmin Lee School of Electronic and Electrical Engineering Graduate School, Kyungpook National University Daegu, Korea (Supervised by Professor Heung-Geun Kim) 

 (Abstract) Instantaneous voltage sag account for the largest proportion of various grid accidents, and the economic losses resulting from them are enormous. To solve this problem, various dynamic voltage restorer(DVR) systems are being researched and developed. Most of these are back-to-back(BTB) types and energy storage(ES) types. Since the BTB type uses the distribution voltage as a voltage source, it can be compensated continuously without a separate storage device, but energy conversion loss occurs because energy conversion must be performed in two or more stages. Also, in order to secure the DC-link voltage, the controller must be complicatedly configured. The ES type utilizes an extra energy storage device and uses it as a voltage source. This results in energy conversion in one stage, resulting in small conversion losses. However, since the unit cost of the energy storage device is high, there is a disadvantage that a lot of cost is incurred to construct the system. Also, due to the capacity limitations of energy storage devices, the compensation time is limited. If additional storage devices are configured to extend the compensation time, the cost will be higher, and this will determine the performance of the system. In this paper, a DVR system consisting of a direct AC-AC converter with a switching cell structure and using an interphase voltage source is presented. The switching cell structure overcomes the current commutation problem, which is a disadvantage of the conventional AC switch, and can prevent damage to the switch due to the short circuit and open of the conventional switch leg. In addition, it can be operated with a high switching frequency because it can be configured as a diode with a fast reverse recovery time instead of a body diode with poor performance. This can reduce the volume and unit cost of passive filters, which are costly in the system configuration. And by using the interphase voltage as a voltage source, it overcomes the disadvantage that the compensation range of the DVR using an ac-ac converter is limited to 50%. This can also compensate for phase jump situations. Compared with the BTB type, the efficiency is good due to energy conversion in one stage, and the time to secure the DC-link voltage is not required, so the dynamic characteristics are better. In addition, control is simple because it is driven through DC reference. Compared with the ES type, there is no limit to the storage device, so the compensation duration is long and the system configuration is economical. Above all, unlike the two conventional compensators that use a voltage source inverter(VSI), the system reliability is excellent and there is no need to apply a bulky and lossy filter. Finally, to prove the feasibility of this paper, we performed a simulation and directly configured the hardware to prove that it is compensable under various voltage sag situations.

VIEW FULL TEXT

https://www.mediafire.com/file/g38eb8e1u62enpt/3-phase+Dynamic+Voltage+Restorer+with+Switching+Cell+Structured+Direct+AC-AC+Converter+Using+Interphase+Voltage.pdf/file

ORIGINAL SOURCE:

http://www.riss.kr/search/detail/DetailView.do?p_mat_type=be54d9b8bc7cdb09&control_no=83dd26b69bdf21a3ffe0bdc3ef48d419&keyword=converter%20%20ac%20ac

ENG. ILDO BET (CEO DA PHB) A HISTORIA DA PRIMEIRA EMPRESA DO BRASIL QUE DESENVOLVIO E INDUSTRIALIZOU AS FONTES CHAVEADAS DE PC E INICIO OS INVERSORES FOTOVOLTAICOS NO BRASIL

Conheça a história de Ildo Bet, um pioneiro no segmento de energia que é um símbolo da inovação tecnológica no país ENGENHEIRO desenvolvedor da fonte de alimentação do microcomputador: Ildo Bet, engenheiro eletrônico, professor universitario e CEO da PHB Solar, a empresa produtora das fontes das urnas eletrônicas do país. Desde 1984, ano de fundação da PHB, uma busca por inovação e qualidade, com seriedade e desenvolvimento tecnológico brasileiro, foram fatores notáveis ​​e importantes na trajetória da PHB Solar. Desta maneira, foi o primeiro fabricante de inversores solares a ser certificada pelo INMETRO no Brasil, atuando na coordenação e elaboração de normas reguladoras e criando forma singular, um laboratório completo para testes e manutenção dos seus próprios produtos. Sempre à frente, a PHB Solar é uma indústria 100% nacional com pioneirismo e competência tecnológica, desenvolvendo soluções para a Geração Distribuída como um todo. A engenharia da PHB oferece respostas rápidas e não depende de uma consulta internacional, sendo uma empresa precursora no mercado de energia solar. 

 O ENGENHEIRO ILDO BET SEMPRE APOIO A PARCERIA ENTRE INDUSTRIA E UNIVERSIDADE,APOIANDO COMO PATROCINADOR OS SEMINARIOS,CONGRESSOS DE ELETRÔNICA DE POTÊNCIA NO BRASIL,E UMA LENDA VIVA DA ELETRÕNICA E INDUSTRIA E UM EXEMPLO DO CAMINHO QUE TEM QUE CONTINUAR BRASIL FAZENDO REATIVAR SUA INDUSTRIA NACIONAL NÃO DEPENDER UNICAMENTE DA CHINA.

FONTE  ORIGINAL DA INFORMAÇÃO:

Edmond Tech Elementar para o seu negócio Financial Services Barueri, São Paulo

PARTICIPAÇÃO WEBINAR "Sistema Elétrico de Potência: Mudanças, desafios e oportunidades"Capítulo Estudantil PELS/IAS do Ramo IEEE UFRN-BRASIL

PARTICIPAÇÃO NO WEBINAR "Sistema Elétrico de Potência: Mudanças, desafios e oportunidades". O webinar contó com uma palestra ministrada pelo Professor Dr. Thiago Rocha da UFRN, além de uma mesa redonda composta pelo Engenheiro Igor Chianca, o Pesquisador Thales Queiroz e pela Engenheira Victória Botelho.Capítulo Estudantil PELS/IAS do Ramo IEEE UFRN BRASIL

Short Circuit Requirements of Power Converters based upon Wide-Bandgap -Author Pappis, DouglasThis work has been accepted by the Faculty of Electrical Engineering / Computer Science of the University of Kassel as a thesis for acquiring the academic degree of Doktor der Ingenieurwissenschaften (Dr.-Ing.).

 

ABSTRACT

In power electronics designs, the evaluation and prediction of potential fault conditions on semiconductors is essential for achieving safe operation and reliability, being short circuit (SC) one of the most probable and destructive among the failures. It can occur externally to the power converter by shortening the load, or internally due to failures on galvanic isolations, stress on passive components, or even in the power semiconductors themselves. Silicon (Si) based power semiconductors have been extensively investigated with regards to their SC capability, although there is still on-going research as their design is being pushed closer to theoretical limits. Recent improvements on Wide-Bandgap (WBG) semiconductors such as Silicon Carbide (SiC) and Gallium nitrite (GaN) enable power electronic designs with outstanding performance, reshaping the power electronics landscape. In comparison to Si, SiC and GaN power semiconductors physically present smaller chip areas, higher maximum internal electric fields, and higher current densities. Such characteristics yield a much faster rise of the devices internal temperatures, worsening their SC performance if compared to Si.

LINK: https://kobra.uni-kassel.de/bitstream/handle/123456789/13296/orig_9783737609777.pdf?sequence=2&isAllowed=y

Método de carga para banco de baterias em fontes ininterruptas de energia que busca garantir o estado de carga completa: corrente pulsada modificado--Cardoso, Renato Tavares (Universidade Federal de Santa Maria)

 

ABSTRACT

Esta dissertação de mestrado tem como proposta o desenvolvimento de um sistema de gerenciamento de carga de um banco de 16 baterias de chumbo ácido, com capacidade de carga de 7Ah, comumente utilizado em Fontes Ininterruptas de Energia (UPS). Este sistema visa garantir que estas baterias cheguem a um estado de carga completo e de forma mais rápida que a convencional. Para isto, foi escolhido fazer a modificação do método de carga de corrente pulsada, com o objetivo de reduzir problemas inerentes do método tomado como base, quando ocorre o intervalo de retirada de energia da bateria, tais como: elevação da tensão do barramento ao retornar a energia para ele, ou, dissipar esta energia em uma resistência, o que acarreta em baixa eficiência do sistema. Para o desenvolvimento do sistema de carga sugerido foi escolhido o conversor estático Full-Bridge Isolado com modulação Phase Shift. Foi feita a modelagem simplificada deste conversor, para a implementação do controle digital, assim como o desenvolvimento prático do mesmo em laboratório. São apresentados os resultados de simulação e experimentais para validar o método. 

 LINK: https://repositorio.ufsm.br/bitstream/handle/1/8576/CARDOSO%2c%20RENATO%20TAVARES.pdf?sequence=1&isAllowed=y

High-voltage power supply for x-ray computed tomography and time-delay compensation of cockcroft-walton circuit Yuki Kajiuchi and Toshihiko Noguchi Canon Medical Systems Corporation, Tochigi, Japan. Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, Hamamatsu, Japan

 

High-voltage power supply for x-ray computed tomography and time-delay compensation of cockcroft-walton circuit Yuki Kajiuchi and Toshihiko Noguchi Canon Medical Systems Corporation, Tochigi, Japan. 2Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, Hamamatsu, Japan. 

Abstract.

 In recent years, an image diagnostic apparatus using X-ray is intensively investigated to reduce the radiation exposures amount. Above all, high-speed control of the high voltage generator to control the X-ray output is a very important issue. A Cockcroft-Walton circuit (CW circuit) is one of the method to generate the high voltage output. However, it has problem of the long time delay in the output response due to the huge capacitive component of the CW circuit. Therefore, it is required to achieve the stable output voltage with a quick transient response, which can be obtained by the time delay compensation technique of the CW circuit. This paper proposes an application of a Smith method to compensate for the time delay of the CW circuit output to reduce the undesirable excessive radiation exposure. AS a result of verification through the computer simulation, it has been confirmed that the overshoot of the output voltage can effectively be suppressed and that the optimal response can be realized without sacrificing the high-speed response. The paper indicates some possibilities of further improvement of the CW circuit output response by introducing the more precise compensation technique to the X-ray computed tomography. 

LINK:https://www.researchgate.net/publication/337182375_High-voltage_power_supply_for_x-ray_computed_tomography_and_time-delay_compensation_of_cockcroft-walton_circuit

변압기 없는 고승압 직류 컨버터용 대칭형 Cockcroft-Walton 회로 (Symmetrical Cockcroft-Walton circuit for Transformerless High Step-Up DC-DC Converter) 차대중*․백지은․고광철** (Dae-Joong Cha․Ji-Eun Baek․Kwang-Cheol Ko)-Journal of the Korean Institute of IIIuminating and Electrical Installation Engineers (2015--

 

변압기 없는 고승압 직류 컨버터용 대칭형 Cockcroft-Walton 회로 (Symmetrical Cockcroft-Walton circuit for Transformerless High Step-Up DC-DC Converter) 차대중*․백지은․고광철** (Dae-Joong Cha․Ji-Eun Baek․Kwang-Cheol Ko) 

Abstract 

High Step-up DC-DC Converters have been demanded for renewable energy applications. Transformer or coupled inductor is generally used to boost output voltage of converters. This methods can relatively obtain high voltage than others, whereas have heavy weight and high cost. To complement these disadvantages, we studied transformerless high step-up DC-DC converter. In various transformerless topologies, Boost converters combined with Cockcroft-Walton have studied. In this paper, we proposed a symmetrical Cockcroft-Walton circuit for transformerless high step-up DC-DC converter. Finally, we simulated proposed converter to compare with existing converter. As a result, proposed converter has higher duty ratio or lower cost than existing transformerless converters which are discussed in this paper.

LINK VIEW FULL TEXT: https://www.koreascience.or.kr/article/JAKO201505041841025.pdf

Cockcroft-Walton Voltage Multiplier Simulation According to Diode Parasitic Capacitance for Xray Generator Designing Xray 발생장치 설계를 위한 다이오드 기생 커패시턴스에 따른 Cockcroft-Walton Voltage Multiplier 시뮬레이션 Im, Gyu-Wan (KONKUK University) ; Mok, Hyung-Soo (KONKUK University) ; Zhu, He-Lin (KONKUK University) 임규완 (건국대학교) ; 목형수 (건국대학교) ; 주학림 (건국대학교)

 ABSTRACT

Due to the recent outbreak of COVID-19 (Coronavirus disease, 2019), The demand for X-ray examinations to make a definitive diagnosis is increasing. In order to obtain high-quality Xray images, the X-ray tube A constant high voltage suitable for the purpose of shooting must be applied to the camera through control. To do this, consider the output voltage characteristics of the power converter. should be designed Therefore, it is mainly used for Xray generators. of the diode using the Cockcroft-Walton Voltage Multiplier. The parasitic capacitance component is the leakage inductance component of the transformer, and the The parasitic inductance component and the output voltage generated by resonance.

LINK VIEW FULL TEXT: https://www.koreascience.or.kr/article/CFKO202026958570456.pdf

NOVA FAMÍLIA DE INVERSORES MULTINÍVEIS ASSIMÉTRICOS COM ESTÁGIO CA-CA E COM REDUZIDO NÚMERO DE COMPONENTES EM CONDUÇÃO--SAMUEL JÓ DE MESQUITA-- Curso de Doutorado em Engenharia Elétrica -Universidade Federal do Ceará--BRASIL

 

RESUMO 

Esta tese propõe uma nova família de inversores multiníveis assimétricos baseados no uso de chaves bidirecionais. Generalizadas relações de tensão entre as fontes de entrada dos inversores cascateados são desenvolvidas e análises comparativas realizadas com as topologias convencionais demonstram uma solução atrativa com relação a redução do número de componentes em condução, além do reduzido emprego de fontes CC isoladas. Soluções topológicas empregando apenas uma fonte CC são apresentadas e a operação com estágio CA-CA desses conversores não necessita de pontes de diodos para confecção das fontes de alimentação dos inversores multiníveis assimétricos como comumente é usado pela comunidade científica. Estratégias de modulação PWM para algumas topologias são propostas e os resultados de simulações são apresentados para validar as análises teóricas. Entre as topologias propostas, foram escolhidas duas de maior complexidade para a validação experimental por meio de um protótipo de 49 níveis na tensão de saída, empregando um transformador toroidal de múltiplos secundários operando em 300 Hz, para a primeira topologia e em 60 Hz para a segunda topologia. Os resultados experimentais para as duas topologias processando 1 kW com tensão de entrada de 48 V e de saída 220 V validam os conversores aqui propostos. Também é validada a proposta dos estados otimizados de comutação dos interruptores bidirecionais. Dessa forma, este trabalho introduz novas topologias de inversores multiníveis assimétricos viáveis até mesmo para operações em baixas potências.

 Palavras-chave: Chaves bidirecionais. Estágio CA-CA. Inversores multiníveis assimétricos. Topologias isoladas. Transformador de múltiplos secundários. Modulação staircase. Modulação híbrida. Modulação PWM.

 ABSTRACT 

This thesis proposes a new family of asymmetric multilevel inverters based on the use of bi-directional switches. Generalized voltage relations among input sources of the cascaded inverters are developed and comparative analyzes with conventional topologies show an attractive solution in relation to the reduction of the number of components in conduction, as well as the reduced number of isolated DC sources. Topological solutions employing only one DC source are presented and the AC-AC operating stage of these converters does not require diode bridges to create the power supplies of asymmetric multilevel inverters as commonly proposed by the scientific community. PWM modulation strategies for some topologies are proposed and validated by simulation results. Among the proposed topologies, two topologies of higher complexity were chosen to validate the studies by means of a 49-level output voltage laboratory prototype, using a toroidal transformer with multiple secondary windings, being one topology operating at 300 Hz, and the second one at 60 Hz. Experimental results for the two topologies processing 1 kW with 48 V input voltage and 220 V output validate these converters as well as the optimized commutation states of the bi-directional switches. In this way, this work introduces new multilevel inverter topologies viable for low power and low voltage operation. 

Keywords: Asymmetrical multilevel inverters. AC-AC conversion. Bi-directional switches. Multi-winding transformers. Hybrid modulation. PWM modulation. Staircase modulation

LINK VIEW FULL TEXT :http://www.gpec.ufc.br/teses/5.pdf

ADVANCED TOPOLOGIES OF HIGH-VOLTAGE-GAIN DC-DC BOOST CONVERTERS FOR RENEWABLE ENERGY APPLICATIONS by AHMAD SAEED Y. ALZAHRANI--MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY--DOCTOR OF PHILOSOPHY in ELECTRICAL ENGINEERING 2018

 CONVERTERS FOR RENEWABLE ENERGY APPLICATIONS by AHMAD SAEED Y. ALZAHRANI MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY 

 In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY in ELECTRICAL ENGINEERING- 2018 

 ABSTRACT

 This dissertation proposes several advanced power electronic converters that are suitable for integrating low-voltage dc input sources, such as photovoltaic (PV) solar panels, to a high voltage dc bus in a 200 − 960 V dc distribution system. The proposed converters operate in the continuous conduction mode (CCM) and offer desirable features such as lowvoltage stresses on components, continuous input currents, and the ability to integrate several independent dc input sources. First, a family of scalable interleaved boost converters with voltage multiplier cells (VMC) is introduced. Several possible combinations of Dickson and Cockcroft-Walton VMCs are demonstrated and compared in terms of the voltage gain, number of components, and input current sharing. This dissertation also presents a novel VMC structure called Bi-fold Dickson. The novel VMC offers equal current sharing between phases regardless of the number of stages, voltage ripple cancellation at each stage, and does not require an output diode. A family of high-voltage-gain multilevel boost converters is presented, with detailed example of the hybrid flyback and three-level boost converter. In this family, the effective frequency seen by the magnetic element is multiple times the switching frequency, and therefore smaller magnetic devices can be used. Theory of operations, steady-state analysis, component selections, simulation, and efficiency analysis are included for each proposed converter. The operation of the proposed converters was further verified with 80 − 200 W hardware prototypes.

LINK: https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=3721&context=doctoral_dissertations

Design and Control Methodology for Improved Operation of a HV Bipolar Hybrid Switched Capacitor Converter J. Delhotal, J. Richards, J. Stewart, J. Neely, J. Flicker, R. Brocato, L. Rashkin Sandia National Laboratories Albuquerque, New Mexico, USA

Design and Control Methodology for Improved Operation of a HV Bipolar Hybrid Switched Capacitor Converter J. Delhotal, J. Richards, J. Stewart, J. Neely, J. Flicker, R. Brocato, L. Rashkin Sandia National Laboratories Albuquerque, New Mexico, USA Email: jneely@sandia.gov Jane Lehr University of New Mexico Albuquerque, New Mexico, USA 

 Abstract— In this work, a novel dc-dc converter topology, an adaptation of the Hybrid Switched Capacitor Circuit (HSCC), is considered for use in high-gain, high voltage applications that also require high efficiency and superior power density. In particular, a bipolar HSCC design is described, and a candidate control methodology is set forth and developed analytically. The converter performance is demonstrated to be consistent with analysis. In addition, the converter is demonstrated to step 460V up to 8.63 kV (gain of 19) at 3.63 kW and nearly 97.0% efficiency. 

LINK VIEW FULL TEXT IN WEB:

https://www.osti.gov/servlets/purl/1473752

DESIGN AND DEVELOPMENT OF POWER PROCESSING UNITS FOR APPLICATIONS IN ELECTRICALLY-PROPELLED SATELLITE SYSTEMS by KARTIKEYA JAYADURGA PRASAD VEERAMRAJU---Requirements for the Degree MASTER OF SCIENCE in ELECTRICAL ENGINEERING--MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY-

 

DESIGN AND DEVELOPMENT OF POWER PROCESSING UNITS FOR APPLICATIONS IN ELECTRICALLY-PROPELLED SATELLITE SYSTEMS by KARTIKEYA JAYADURGA PRASAD VEERAMRAJU

 A THESIS Presented to the Graduate Faculty of the MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY In Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE in ELECTRICAL ENGINEERING 2020 

 ABSTRACT 

Electrospray technology provides a way to ionize specialized liquids by applying high voltages across a sharp porous tip and a metallic mesh. This technology is widely used in the field of mass spectroscopy for generating ions for testing purposes. The dawn of nano-satellites posed new challenges in the miniaturization of many conventional satellite sub-systems. One significant challenge faced in such a process was the miniaturization of the propulsion system. Electrosprays have started to find their application in the field of Aerospace Engineering and now are formally known as Electrospray Thrusters. These thrusters provide high specific impulse and are attractive substitutes to conventional gas propelled thrusters as they can be scaled down in size and can also provide extended mission times. Some of the new challenges faced in such applications are the generation of high voltages from a lowvoltage onboard battery, grounding, spacecraft charging, clearance, and reliability issues for long term usage. In this work, a complete design process is developed for the realization of such high voltages suitable for interfacing with an electrospray thruster. Simulation models for a new type of converter are assessed, and its feasibility is discussed. A hardware prototype is implemented, and the practical results are assessed. An analysis of the converter is presented, and the semiconductor and passive components are selected. Magnetic components are designed based on the analysis. Parallels are drawn between the theoretical and prototype model of the concept converter. Finally, the firmware of the converter is explained, and the communication protocol of the PPU is delineated. As the boards designed for the converter have to sustain high voltages and reliably operate in unfavorable environments, special PCB layout considerations must be used, which also forces a designer to look for various other materials for the PCB fabrication.

 LINK VIEW FULL TEXT IN WEB:

https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=8938&context=masters_theses

Characterization and Design of HighSwitching Speed Capability of GaN Power Devices in a 3-Phase Inverter-Rémi PERRIN-THESE de DOCTORAT DE L’UNIVERSITE DE LYON opérée au sein de Laboratoire AMPERE

 

Characterization and design of the switching frequency rise of a 3-phase inverter with GaN transistors by Rémi Perrin

 Abstract 

The French industrial project MEGaN aims to develop a power module based on HEMT compost in GaN. One of the industrial applications concerns aeronautics with a high constraint in galvanic isolation (> 100 kV / s) and in ambient temperature (200 ° C). The thesis work was focused on a power module brick (650 V 30 A inverter arm). The objective is to achieve a prototype of thin form factor, 30 cm2 and embedding all the driver functions, driver power supply, bus capacity and phase current sensor. This objective implies high energy efficiency, and respect for galvanic insulation while the surface stress is high. The manuscript, in addition to the state of the art relating to the power module and in particular that based on GaN HEMT transistor, discusses a micro-transformer-based control signal isolation solution. Micro-transformer prototypes were characterized and aged for 3000 hours to assess the robustness of the solution. The work contributed to the characterization of several GaN components in order to mature models for circuit simulation of converter topology. Within the MEGaN collaborative work, our contribution did not concern the design of the integrated circuit (grid driver), while having participated in the validation of the specifications, but a power supply strategy for the grid driver. A first isolated power supply proposal for the gate driver favored the use of low-voltage GaN components. The resonant flyback topology with clamp makes it possible to get the most out of these GaN components but poses the constraint of the power transformer. Several technologies for the realization of the transformer have been validated experimentally and in particular an original proposal for the burial of the magnetic component within a high-temperature polymer substrate. In particular, an inexpensive manufacturing process makes it possible to obtain a reliable device (1000 h of cycling between - 55; + 200 ° C), with an intrinsic efficiency of 88% for 2 W transferred. The parasitic insulation capacity is reduced compared to previous prototypes. Two prototypes of highly integrated power supplies use either low voltage GaN transistors (2.4 MHz, 2 W, 74%, 6 cm2), or a dedicated integrated circuit in CMOS SOI technology, designed for the application (1.2 MHz, 2 W, 77%, 8.5 cm2). The manuscript then proposes an integrable solution for measuring the phase current of the bridge arm, based on a magnetoresistance. The experimental comparison with respect to a shunt resistance solution. Finally, two converter prototypes are described, one of which has been the subject of an experimental validation demonstrating reduced switching losses.

VIEW FULL TEXT :http://theses.insa-lyon.fr/publication/2017LYSEI001/these.pdf

Design and characterization of a three-phase current source inverter using 1.7kV SiC power devices for photovoltaic applications-Présentée par Luís Gabriel ALVES RODRIGUES Laboratoire de Génie Electrique de Grenoble dans l'École Doctorale Electronique, Electrotechnique, Automatique et Traitement du Signal-

 

Abstract 

Classically, the energy conversion architecture found in photovoltaic (PV) power plants includes solar arrays delivering a maximum voltage of 1kV followed by a step-up chopper connected to a three-phase Voltage Source Inverter. This multistage conversion system (DC/DC + DC/AC) is then connected to the medium-voltage grid through a low-voltage/medium-voltage transformer. In order to simplify the PV systems, this research work focuses on the study and implementation of a DC/AC topology employing a single power processing stage: the three-phase Current Source Inverter (CSI). To deal with the inconvenient of high conduction losses when implementing this topology, wide-bandgap Silicon Carbide (SiC) semiconductors are used, allowing to efficiently convert energy while keeping a relatively high switching frequency. Nonetheless, since the available power semiconductor modules on the market are not compatible with the CSI, a novel 1.7kV SiC-based voltage bidirectional module is developed in the context of this thesis. Hence, the dynamic characterization of the new SiC device is carried out and serves as the basis for the design of a 60kW CSI prototype. Finally, the inverter efficiency is evaluated at nominal operating conditions, employing both a calorimetric and electrical methods. The obtained results confirm the CSI ability to operate efficiently at high switching frequencies (η>98.5% @60kHz). The originality of this work lies mainly in the design, characterization and implementation of the new 1.7kV full-SiC power module adapted to the CSI topology. Keywords: Power electronics, DC/AC converters, Current Source Inverter (CSI).

VIEW FULL TEXT : https://tel.archives-ouvertes.fr/tel-02476261/document

A Study on a Single-phase Control Algorithm of 4-LEG type PCS (Power Conditioning System)for Micro-grid Application by Seung Ho, Kim -Department of Electronic and Electrical Engineering The Graduate School Korea University of Technology and Education

마이크로그리드용 4-LEG 방식 PCS의 각상 개별제어 알고리즘에 관한 연구

 A Study on a Single-phase Control Algorithm of 4-LEG type PCS for Micro-grid Application

BY KIM SEUNG HO

Graduate School of Korea University of Technology and Education Electrical and Electronic Communication Engineering Electrical Engineering

ABSTRACT

AC-common bus microgrid system can overcome several weaknesses of DC microgrid system by interconnecting DC/AC inverters for renewable energy with AC network. Nevertheless, unbalanced loads in island and small community electric power system can make performances of AC microgrid system getting worse. These are because of limited voltage regulation capability and mixed power flow in voltage source inverter. In other to overcome the unbalanced load condition, this paper proposes voltage and current control algorithm of 4-LEG inverter based on single phase d-q control method, and also proposes the modeling of voltage controller using Matlab/Simulink S/W. From the S/W simulation and experiment of 250kW proto-type inverter, it is confirmed that the proposed algorithm is useful tool for design and operation of AC microgrid system.

VIEW FULL TEXT:

http://kut.dcollection.net/public_resource/pdf/200000083347_20211104232924.pdf

ANALYSIS AND OPERATION OF A MICROGRID WITH PHOTOVOLTAIC SOURCES-A Thesis Presented to The Academic Faculty By Juan C. Lazarte-In Partial Fulfillment Of the Requirements for the Degree Master of Science in Electrical and Computer Engineering-Georgia Institute of Technology

 VIEW FULL TEXT: https://smartech.gatech.edu/bitstream/handle/1853/59951/LAZARTEMENDOZA-THESIS-2018.pdf

Straight Facts about Linear MOSFETs and their Applications BY José Padilla, Director Product Marketing; Aalok Bhatt, Product Marketing Engineer; Vladimir Tsukanov, Senior Principal R&D, Littelfuse-BODO POWER SYSTEM

Straight Facts about Linear MOSFETs and their Applications Linear-mode applications such as class-A audio amplifiers, active DC-link discharge, battery charge-discharge, inrush current limiter, low-voltage DC motor control or electronic loads demand the power MOSFETs to be operated within the current saturation region. Standard MOSFETs are prone to ETI when used in linear-mode applications leading to possible device destruction. Linear MOSFETs are the most appropriate choice for linear-mode applications to ensure reliable operation. José Padilla, Director Product Marketing; Aalok Bhatt, Product Marketing Engineer; Vladimir Tsukanov, Senior Principal R&D, Littelfuse

Introduction – What is linear-mode operation and why is it required Power MOSFET’s output characteristic can be divided in to three distinct regions namely ohmic region, non-linear region, and saturation or active region as displayed in Figure 1. In the ohmic region, the drain current ID is directly proportional to the drain-source voltage VDS for a given gate-source voltage VGS. The MOSFET acts as a resistor in this operation mode with a value equal to its on-state resistance RDS(ON). In the non-linear region, the MOSFET’s resistance behaves non-linearly and the rate of increase of ID with VDS slows down. In the active region, the MOSFET’s channel is saturated with majority charge carriers. In this region, ID is independent of VDS. ID is governed only by VGS and it remains constant for any given VDS. In other words, the MOSFET exhibits the behavior of a constant current sink. This operating mode is commonly known as linear operation mode of power MOSFETs. In this operating mode, the MOSFETs typically dissipate higher power levels than they would in the more common switched-mode applications due to simultaneous occurrence of high voltage and current[1].

VIEW FULL TEXT: MAGAZINE BODO POWER SYSTEM -OCTOBER 2021

LINK: https://www.bodospower.com/

Recherches d’optimums d’énergies pour charge/décharge d'une batterie à technologie avancée dédiée à des applications photovoltaïques T H E S E préparée au Laboratoire d’Analyse et d’Architecture des Systèmes du CNRS en vue de l’obtention du DOCTORAT DE L’UNIVERSITE DE par Jean-François REYNAUD

 Recherches d’optimums d’énergies pour charge/décharge d'une batterie à technologie avancée dédiée à des applications photovoltaïques 

T H E S E préparée au Laboratoire d’Analyse et d’Architecture des Systèmes du CNRS en vue de l’obtention du DOCTORAT DE L’UNIVERSITE DE TOULOUSE

Délivré par l’Université Toulouse III – Paul Sabatier 

Discipline : Génie Electrique présentée et soutenue par Jean-François REYNAUD 

LINK: http://thesesups.ups-tlse.fr/1482/1/2011TOU30136.pdf

Système d’alimentation photovoltaïque avec stockage hybride pour l’habitat énergétiquement autonome -Akassewa Tchapo Singo- Thèse présentée pour l’obtention du titre de Docteur de l’Université Henri Poincaré, Nancy-I en Génie Electrique

 Thèse présentée pour l’obtention du titre de Docteur de l’Université Henri Poincaré, Nancy-I en Génie Electrique par Akassewa Tchapo SINGO Ingénieur ENSEM Système d’alimentation photovoltaïque avec stockage hybride pour l’habitat énergétiquement autonome .

Soutenue publiquement le 3 février 2010

 INTRODUCTION GENERALE 

Avec l’arrivée du nouveau millénaire, les débats sur l’avenir énergétique de la planète se sont intensifiés compte tenus des besoins sans cesse croissants dans le domaine et les conséquences que cela peut engendrer à moyen terme. En effet, l’évolution démographique et le développement de certaines zones géographiques, l’Asie aujourd’hui, l’Amérique Latine et la Russie demain, laissent présager une augmentation considérable de la consommation en énergie. A ce rythme, les réserves en énergies fossiles ne pourront assurer les besoins que pour quelques décennies encore, entrainant des situations de pénurie dont les prémices se sont faites ressentir à travers la crise du pétrole de ces deux dernières années. Les gisements de ressources énergétiques d’origines fissiles, même si elles offrent une alternative à court/moyen terme, posent quant à elles de réels problèmes environnementaux liés au traitement des déchets radioactifs et au démantèlement des centrales nucléaires obsolètes. Une première piste à cette crise annoncée étant la diminution de la consommation énergétique, c’est ainsi que sont apparus sur le marché, ces dernières années, des appareils de faible consommation de classe A ou A+ (réfrigérateurs, laves linge, ampoules basse consommation, …). En parallèle, il faut développer de nouvelles sources d’énergie propres et renouvelables. A ce sujet, le soleil, le vent, la biomasse, la mer, … apparaissent comme des énergies inépuisables et facilement exploitables. Ainsi, d’après l’Agence Internationale de l’Energie (AIE), si l’on prend l’exemple du soleil, une surface de 145000km² (4% de la surface des déserts arides) de panneaux photovoltaïques (PV) suffirait à couvrir la totalité des besoins énergétiques mondiaux. Au-delà de toutes considérations hypothétiques, il apparait que le photovoltaïque se présente comme une solution d’avenir car il offre une multitude d’avantages : · la production de cette électricité renouvelable n'émet pas de gaz à effet de serre, il faut cependant réduire l’impact environnemental de la fabrication du système, · la lumière du soleil étant disponible partout et quasi-inépuisable, l'énergie photovoltaïque est exploitable aussi bien en montagne, dans un village isolé que dans le centre d'une grande ville, et aussi bien au Sud que dans le Nord, · l'électricité photovoltaïque peut être produite au plus près de son lieu de consommation, de manière décentralisée, directement chez l'utilisateur, ce qui la rend accessible à une grande partie de la population mondiale.

LINK: https://hal.univ-lorraine.fr/tel-01748214/document

Optimal sizing and control of energy storage systems for the electricity markets participation of intelligent photovoltaic power plants Andoni Saez de Ibarra Martinez de Contrasta UNIVERSITE GRENOBLE ALPES

 Optimal sizing and control of energy storage systems for the electricity markets participation of intelligent photovoltaic power plants Andoni Saez de Ibarra Martinez de Contrasta 

 THÈSE Pour obtenir le grade de DOCTEUR DE LA COMMUNAUTE UNIVERSITE GRENOBLE ALPES

 Spécialité : Génie Electrique 

 Dimensionnement et contrôlecommande optimisé des systèmes de stockage énergétique pour la participation au marché de l'électricité des parcs photovoltaïques intelligents 

Thèse soutenue publiquement le 7 octobre 2016, devant le jury composé de : M. Cristian NICHITA Professeur à l’Université Le Havre, Président M. Bruno BURGER Fraunhofer ISE, Rapporteur M. Luis MARTINEZ SALAMERO Professeur à l’Universitat Rovira i Virgili, Rapporteur M. Ionel VECHIU Professeur à l’ESTIA, Rapporteur M. Seddik BACHA Professeur à l’Université Grenoble Alpes, Directeur de thèse M. Vincent DEBUSSCHERE Maître de Conférences Grenoble INP, Co-encadrant de thèse M. Aitor MILO IK4-IKERLAN Technology Research Centre, Co-encadrant de thèse Mme. Haizea GAZTAÑAGA IK4-IKERLAN Technology Research Centre, Examinatrice M. Tuan TRAN QUOC CEA-INES, Invité

Abstract 

The present PhD deals with the integration of intelligent photovoltaic (IPV) power plants in the electricity markets in an environment subject to free competition. The IPV power plants are those that include energy storage systems to reduce the variability and to provide the entire group a controllability increase. These technical objectives are obtained thanks to the bidirectional exchanging and storing capability that the storage system contributes to, in this case, battery energy storage system (BESS). In order to obtain the maximum profitability of the BESS, the sizing must be optimized together with the control strategy that the BESS will be operated with. In the present PhD, once the most performing battery energy storage technology has been selected, the lithium-ion technology, an innovative IPV power plant electricity market participation process is proposed which optimizes both the sizing and the energy management strategy in the same optimization step. This optimization process together with the electricity market participation has been applied in a real case study, confirming that this procedure permits to maximize the economic profitability of this type of generation. Keywords: photovoltaic power plant, energy storage system, grid, optimization, electricity markets, sizing, energy management strategy.

VIEW FULL TEXT: https://tel.archives-ouvertes.fr/tel-01417133/document

Design and Implementation of a Radiation Hardened GaN Based Isolated DC-DC Converter for Space Applications Victor Turriate- Virginia Polytechnic Institute and State University - Master of Science In Electrical Engineering

 

Design and Implementation of a Radiation Hardened GaN Based Isolated DC-DC Converter for Space Applications Victor Turriate-Gastulo Thesis submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Master of Science In Electrical Engineering

ABSTRACT 

Power converters used in high reliability radiation hardened space applications trail their commercial counterparts in terms of power density and efficiency. This is due to the additional challenges that arise in the design of space rated power converters from the harsh environment they need to operate in, to the limited availability of space qualified components and field demonstrated power converter topologies. Recently released radiation hardened Gallium Nitride (GaN) Field Effect Transistors (FETs) with their inherent radiation tolerance and superior performance over Silicon Power Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), however, offer a promising alternative to improve power density and performance of space power converters. This thesis presents a practical implementation of the Phase Shifted Full Bridge DC-DC Isolated converter with synchronous rectification for space applications using newly released radiation hardened GaN FETs. A survey outlining the benefits of new radiation hardened GaN FETs for space power applications compared to existing radiation hardened power MOSFETs is included. In addition, this work summarizes the main design considerations to implement the selected converter topology for space applications. Furthermore, the overall design process followed to design the DC-DC converter power stage, as well as a comprehensive power loss analysis are included. This work also includes details to implement a conventional hard-switched Full Bridge DC-DC converter using radiation hardened GaN FETs for this application. An efficiency and component stress comparison was performed between the hard-switched Full Bridge design and the Phase Shifted Full Bridge DC-DC converter design. This comparison highlights the benefits of phase shift modulation (PSM) and zero voltage switching (ZVS) for GaN FET applications. Furthermore, different magnetic designs were characterized and compared for efficiency in both converters. The DC-DC converters implemented in this work regulate their outputs to a nominal 20 V, delivering 500 W from a nominal 100 V DC Bus input. Failure mode and effects analysis (FMEA) and protection circuitry required for complete radiation qualification of the Phase Shifted Full Bridge DC-DC converter topology are not addressed by this work.

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https://vtechworks.lib.vt.edu/bitstream/handle/10919/98232/Turriate_VO_T_2018.pdf?sequence=1&isAllowed=y

Multiphase Design and Control Techniques Applied to a Forward Micro-Inverter TESIS DOCTORAL Autor: David Meneses Herrera Ingeniero Industrial por la Universidad Politécnica de Madrid DEPARTAMENTO DE AUTOMÁTICA, INGENIERÍA ELECTRÓNICA E INFORMATICA INDUSTRIAL

 

Multiphase Design and Control Techniques Applied to a Forward Micro-Inverter 

 TESIS DOCTORAL Autor: David Meneses Herrera Ingeniero Industrial por la Universidad Politécnica de Madrid 

 DEPARTAMENTO DE AUTOMÁTICA, INGENIERÍA ELECTRÓNICA E INFORMATICA INDUSTRIAL Universidad Politécnica de Madrid

 Abstract 

 In the last decade the photovoltaic (PV) installed power increased with an average growth of 49% per year and it is expected to cover the 16% of the global electricity consumption by 2050. Most of the installed PV power corresponds to grid-connected systems, with a significant percentage of residential installations. In these PV systems, the inverter is essential since it is the responsible of transferring into the grid the extracted power from the PV modules. Several architectures have been proposed for grid-connected residential PV systems, including the AC-module technology. An AC-module consists of an inverter, also known as micro-inverter, which is attached to a PV module. The AC-module technology offers modularity, redundancy and individual MPPT of each module. In addition, the expansion of this technology will enable the possibility of economies of scale of mass market and “plug and play” for the user, thus reducing the overall cost of the installation. However, the micro-inverter must be able to provide the required voltage boost to interface a low voltage PV module to the grid while keeping an acceptable efficiency in a wide power range. Furthermore, the quality standards must be satisfied and size and lifetime of the solutions must be always considered. In this thesis a single-stage forward micro-inverter with boundary mode operation is proposed to address the micro-inverter requirements. The transformer in the proposed topology remains as in the classic forward converter and bidirectional switches in the secondary side allows direct connection to the grid. In addition the selected control strategy allows high power factor current with a simple implementation. The operation of the topology is presented and the main design issues are introduced. With the intention to propose a simple and low-cost solution, an analog controller for a PFC operated in boundary mode is utilized. The main necessary modifications are discussed, with the focus on the zero current detection (ZCD) and the compatibility of the controller with a MPPT algorithm. The experimental results show the limitations of the selected analog controller implementation and the transformer is identified as a main losses contributor. The main objective of this thesis is to contribute in the application of control and design multiphase techniques to the PV micro-inverters. Two different multiphase configurations have been applied to the forward micro-inverter proposed in this thesis. The first one consists of a parallel-series connected variation which enables the use of low turns ratio, i.e. well coupled, transformers to achieve a proper voltage boost with an improved performance. This multiphase configuration implements BCM control at maximum load however. With this control method the switching frequency increases significantly for light load operation, thus jeopardizing the efficiency. Therefore, in order to keep acceptable weighted efficiency levels, DCM operation is selected for low power conditions. The second multiphase variation considered in this thesis is the interleaved configuration with two different phase shedding techniques: depending on the DC power extracted from the PV panel, and depending on the demanded instantaneous power. The application of interleaving techniques is interesting in PV grid-connected inverters for the possibility of flat efficiency behavior in a wide power range. The interleaved variations of the proposed forward micro- inverter are operated in DCM to avoid the current loop, which is important when the number of phases is large. The adequate transformer cores for all the multiphase configurations are selected according to the area product parameter and a detailed design of each required transformer is developed. With this information and simulation results, the impact in size and efficiency of the number of transformer used can be assessed. The considered multiphase topologies are compared in this thesis according to the results of the introduced analysis.

 LINK VIEW FULL TEXT:https://oa.upm.es/39988/1/DAVID_MENESES_HERRERA.pdf