태양전지 및 연료전지용 소용량 하이브리드 인버터 설계 및 구현 Design and Implementation of Hybrid Small-Sized Power Inverter for PV and Fuel Cell

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 

http://www.riss.kr/link?id=T15112929

Seoul: Kwangwoon University Graduate School, 2019 

 Dissertation Thesis (Doctoral)-- Kwangwoon University Graduate School: Department of Electrical Engineering 2019.2 Year of issue 2019 2018年12月7日

 ABSTRACT

 Design and Implementation of Hybrid Small-Sized Power Inverter for PV and Fuel Cell As a major source of power for robots and drones that emerged as key elements of the Fourth Industrial Revolution era, solar cells, fuel cells, and lithium-ion batteries are receiving spotlight as batteries that can produce high power for long periods of time. Especially, the global market for solar cells and fuel cells is expanding as new and renewable energy sources. While inverter demand is essential for efficient operation of batteries and studies of high-quality inverter technologies such as solar energy, energy storage devices such as robots, drones, etc. As hybrid technologies that supplement solar energy and fuel cells in battery power are commercialized in the U.S., including Japan, it is imperative to study new power converters and control technologies that add green power to secondary batteries. The purpose of this paper is to design and implement a small-capacity hybrid inverter system for solar cells and fuel cells that efficiently operate robots and controllers, communications and various mission equipment by merging solar cells, fuel cells and lithium-ion batteries. To this end, the electrical model for solar cells, fuel cells and lithium-ion batteries is first established and the architecture of the hybrid inverter system is proposed based on these models. After each component has been designed and verified, the entire system is verified and finally the proposed smallcapacity hybrid inverter system is demonstrated by mounting the actual robot's power system. This paper proposes the structure and function of hybrid inverter systems by establishing an electrical equivalent linear model, understanding the power characteristics of solar cells, fuel cells and lithium-ion batteries with different principles of energy generation. Each module proposes a new method of impedance matching maximum power point tracking control technology that is essential to the design of the buck converter for solar cells and fuel cells. It also designs an interleaved, bidirectional DC-DC converter with a high-passing ratio for optimal charging of lithium-ion batteries and proposes an efficiency analysis method in the multiplier mode. In addition, it proposes a two-way DC-DC converter that simultaneously takes into account efficiency and stability. The proposed hybrid inverter system is implemented as a small-capacity hybrid interver system for solar cells and fuel-cells by proving its effectiveness through simulation and practical experiments at the module and system level and by applying it to actual mobile robots. In conclusion, the research proposed a small hybrid inverter system for solar cells and fuel cells provides power conversion solutions suitable for robots, drones, wearable devices, and mobile electronics. Futhermore, Combined with other energy storage devices other than lithium-ion batteries, it is also able to be applied as a power converter for large capacity ESS. Therefore, it presents the possibility of independent products as modules and system technologies for low-cost, long-term, and high-power inverter technologies in the future renewable energy sector.

LINK: http://www.riss.kr/search/detail/DetailView.do?p_mat_type=be54d9b8bc7cdb09&control_no=513893263f37c12effe0bdc3ef48d419&keyword=HYBRID%20INVERTER

【パワエレ】LLCコンバータの簡易設計 Design Example of LLC Converter-[Power electronics] Simple design of LLC converter Design Example of LLC Converter

 

Self-powered Sensor Monitoring System in Industrial Internet of Things using Off-resonance Piezoelectric Energy Harvesting Techniques by Jae Yong Cho -Dissertation for the degree of Doctor of Philosophy-Graduate School of Hanyang University-

 Dissertation for the degree of Doctor of Philosophy Self-powered Sensor Monitoring System in Industrial Internet of Things using Off-resonance Piezoelectric Energy Harvesting Techniques 

by Jae Yong Cho

 Graduate School of Hanyang University February 2019 

Department of Electrical Engineering Graduate School of Hanyang University 

 ABSTRACT 

 The main keyword in the era of the fourth industrial revolution is IIoT (Industrial Internet of Things) that enables the interactive network between devices, vehicles, home appliances, and other items embedded with electronics, software, sensors, actuators and etc. To realize IIoT world, there are key technologies; sensors, microcontroller, connectivity, and energy management. Especially, in terms of energy management, many researches have been carried out about self-powering, a battery-less device from energy harvesting. At the center, there is piezoelectric energy harvesting technology, which converts mechanical energy into electrical energy. Lots of researches about piezoelectric energy harvesting have been carried about because piezoelectric material has relatively high power density and is easily applicable to various infrastructures like road, building, and factory close to our daily lives. Ultimately, the goal of this technology is heading for energy saving and simple installation of sensors used for monitoring structural condition without inconveniences such as the replacement of the batteries and the complexity of the cables. In this dissertation, the research about design and fabrication of off-resonance type piezoelectric energy harvesting systems for IIoT sensor was discussed. Because the actual frequency environment in a real field is not geared to resonant frequencies, previous piezoelectric energy harvesting systems were difficult to harvest ambient energy efficiently. We developed the techniques for harvesting energy efficiently through new structures of off-resonance piezoelectric energy harvesters according to various frequency environment. As the final step, the demonstration study was conducted to illustrate IIoT platform as V2I (Vehicle to Infrastructure) system from the piezoelectric energy harvesting techniques. The developed harvester was fabricated and installed on the highway (Yeoju-si, Gyeonggi-do, South Korea). As a result, self-powered temperature sensor monitoring system was constructed using the energy harvester to be able to operate wireless temperature sensor (eZ430-RF2500, Texas Instruments, USA) without battery. Finally, the system was established to inform a driver of the freezing condition on the road in advance as V2I system. First, the design and fabrication of the resonance dependent type energy harvester were conducted. We have developed the piezoelectric energy harvester using wind that is dependent on the resonant frequency, which is a key component of piezoelectric power generation. The experiment result showed that the difference in power generation characteristics when and when not at resonant frequencies makes difficult for the energy harvester to be applied to actual industrial environments where frequencies vary. Finally, it is essential to develop energy harvesters considering these diverse frequency environments. Second, the studies of energy harvesters optimized for different types of frequency environments in industries were conducted. The frequency environment was divided in four conditions (single frequency, multi frequency, random frequency, and intermittent frequency). For single, multi and random frequency conditions, a magneto-mechanical system was applied as the method of harvesting more energy utilizing magnetic forces. For an intermittent condition, system design was conducted as the method to overcome the offresonance region. In single frequency environment, conveyor belts within a smart factory were presented as an experimental environment and the study was conducted to overcome an environment using magnets on the core belt that is much lower than the resonant frequencies of a typical piezoelectric device. In multi frequency environment, water pipes located in plants or buildings were presented as an experimental environment, and to harvest more energy, a hybrid system using piezoelectric energy harvester and electromagnetic energy harvester was studied. In a random frequency environment, the railway was proposed as experimental condition and the magnetic pendulum energy harvester utilizing inertial moments was developed. The energy harvester for the intermittent frequency environment was studied, taking into account the wireless switch that is sometimes pressed by humans as one of the intermittent frequency environments. Third, the research was carried out on the energy harvesting circuit, which is essential for applying the energy harvester to the actual IIoT environment. Preferentially, equivalent circuit modeling of piezoelectricity and impedance matching study was conducted to deliver maximum power. The DC-DC converter study was also conducted to convert high voltage of the piezoelectricity into low voltage so that actual sensor applications can be self-driven by the energy harvester. Additionally, the research was conducted to create the desired output voltage, and finally to establish the wireless communication interface.

VIEW FULL THESIS: https://www.mediafire.com/file/41mjvvokgymxczk/Self-powered+Sensor+Monitoring+System+in+Industrial+Internet+of+Things+using+Off-resonance.pdf/file

Projeto otimizado para minimização de perdas em um conversor bidirecional aplicado a sistemas autônomos de iluminação-Tese de doutorado- Autoria:Duarte, Renan Rodrigo-UNIVERSIDADE FEDERAL DE SANTA MARIA-BRASIL

 

RESUMO 

O presente trabalho apresenta o desenvolvimento de um sistema autônomo de iluminação pública baseado em energia solar fotovolaica e diodos emissores de luz (LEDs). O sistema deve ser capaz de carregar um banco de baterias durante o dia através de um arranjo fotovoltaico e suprir uma carga LED durante a noite. Um conversor bidirecional com transistores de nitreto de gálio (GaN) é utilizado de forma a obter uma estrutura com elevado rendimento e, com isso, otimizar o tamanho do banco de baterias e arranjo fotovoltaico para maximizar a autonomia do sistema ou reduzir os custos de produção, dependendo dos objetivos da aplicação. Foi desenvolvida uma metodologia completa e otimizada para o projeto dos elementos deste sistema autônomo de iluminação. Esta metodologia baseia-se em um algoritmo de busca discreta que avalia um conjunto de componentes disponíveis comercialmente para determinar a melhor combinação de componentes e o melhor ponto de operação do circuito, de modo a minimizar as perdas de energia ao longo do período de operação do sistema. Neste documento é apresentada, inicialmente, uma revisão bibliográfica de aspectos teóricos relacionados aos sistemas autônomos de iluminação, como fonte fotovoltaica, baterias, carga LED, topologias de conversores e soluções comerciais disponíveis. Uma revisão sobre interruptores GaN também é apresentada, abrangendo seu histórico, princípio de funcionamento, características e estado da arte da tecnologia em termos de dispositivos comerciais. Para validar experimentalmente a topologia proposta, um protótipo de 100 W com frequência de comutação arbitrária foi desenvolvido e avaliado. No modo carregador de bateria, o circuito opera em 250 kHz e apresenta eficiências maiores que 92% em toda a faixa de potência com um valor máximo de 97,3%. No modo driver de LED, a frequência de operação escolhida foi de 345 kHz e uma eficiência máxima de 95,8% foi obtida. Para a validação da metodologia de projeto proposta, quatro conversores com potências de 30 W em modo driver e 150 W em modo carregador foram implementados e testados em diferentes pontos de operação. Com isso, comprovou-se que, considerando um conjunto de componentes, a metodologia é capaz de determinar o melhor ponto de operação para maximizar o rendimento, e, considerando diferentes conjuntos de componentes, determinar o melhor em termos de redução da energia perdida, de forma a maximizar a autonomia do sistema.

VER TESE COMPLETA:

 https://repositorio.ufsm.br/bitstream/handle/1/25767/TES_PPGEE_2022_DUARTE_RENAN.pdf?sequence=1&isAllowed=y