Design and implementation of a GaN based dual active bridge converter for electric vehicle charger-CANDIDATE: Marco Giacomazzo-INDUSTRIAL ENGINEERING DEPARTMENT Master’s degree in Electrical Energy Engineering-University of Padua

 

Industrial Engineering Department Master’s degree in Electrical Energy Engineering

Master's thesis in Electrical Energy Engineering 

SUPERVISOR: Prof. Manuele Bertoluzzo 

CO-SUPERVISOR: M.Sc. Konstantin Siebke 

CANDIDATE: Marco Giacomazzo

 ACADEMIC YEAR 2019-2020

 Design and implementation of a GaN based dual active bridge converter for electric vehicle charger 

 Abstract

 In questa tesi si affronta lo studio del convertitore doppio ponte attivo, operante alla frequenza di 500 [kHz]; viene inoltre presentata la progettazione del trasformatore ad alta frequenza ed infine viene descritta una possibile alternativa al classico controllo con singolo sfasamento tra i due ponti attivi, al fine di estendere il funzionamento in soft switching anche con piccoli livelli di potenza trasmessa, in particolare durante l'ultimo stadio di carica della batteria.

LINK:http://www.mediafire.com/file/alauj0ohf9v15wl/Giacomazzo_Marco_1159867.pdf/file

A Study on the Efficiency Improvement of Inverter for Automotive using SiC MOSFET SiC MOSFET를 이용한 차량용 INVERTER 효율 향상에 관한 연구--KOREA NATIONAL UNIVERSITY OF TRANSPORTATION

 A Study on the Efficiency Improvement of Inverter for Automotive using SiC MOSFET

 SiC MOSFET를 이용한 차량용 INVERTER 효율 향상에 관한 연구 

Author

Seongki Ahn

KOREA NATIONAL UNIVERSITY OF TRANSPORTATION

Abstract 

DC-AC inverter units for vehicles are supplied with input voltage DC 12V to 24V using vehicle batteries and converted to single phase AC 220V. Automotive DC-AC inverters have been used in some places with generators where electricity cannot be drawn up, such as election campaign vehicles, but they are increasingly turning into inverters due to engine noise and smoke problems in generators. In particular, the need to use AC power in camping vehicles and food trucks increased due to the influence of the five-day workweek, and the increasing use of non-starting air conditioners in large vehicles such as trailers. In addition, with the increasing use of personal electrical appliances such as laptops and mobile phones, the demand for DC-AC inverters for vehicles is expected to surge in the coming months in multi-use transportation means such as buses and railway vehicles. MOSFET, which is a power semiconductor device, is a major component that is needed for DC-AC inverters for vehicles. Although silicon (Si : Silicon) power semiconductor device has been used as a key power conversion component of inverter system until now, achieving fast/lightening and high power generation of power unit that consists of silicon element is reaching its limit. Silicon carbide (SiC : Silicon Carbide) power semiconductor is the next generation power semiconductor to replace the limit situation that Si power semiconductor has. In this paper, we measured the loss of conduction, switching loss, efficiency characteristics, and the temperature of the main parts for Si / SiC MOSFET. In the conduction loss experiment, the loss value of SiC MOSFET compared to Si MOSFET for one cycle is approximately 61.3(%). The switching loss experiment showed that SiC MOSFET losses were small, with about 49.6(%) at Turn-on and approximately 49.2(%) at Turn-off against Si MOSFET. This was immediately confirmed to be low temperature in each part of the inverter. In particular, it was found that the temperature difference at the transformer core with the highest temperature varies from the load of 600(W) to 15.1(°C). In the experiment of efficiency characteristics, the maximum efficiency of 93.5(%) was obtained, and the efficiency improvement of up to 2.8(%) compared to the inverter with Si MOSFET was achieved. The temperature measurement test also shows that most parts temperature is low in the inverter employing SiC MOSFET. The application of SiC MOSFET to the efficiency of inverter was proved to be reasonable as the performance of inverter with SiC

In this paper, we measured the loss of conduction, switching loss, efficiency characteristics, and the temperature of the main parts for Si / SiC MOSFET. In the conduction loss experiment, the loss value of SiC MOSFET compared to Si MOSFET for one cycle is approximately 61.3(%). The switching loss experiment showed that SiC MOSFET losses were small, with about 49.6(%) at Turn-on and approximately 49.2(%) at Turn-off against Si MOSFET. This was immediately confirmed to be low temperature in each part of the inverter. In particular, it was found that the temperature difference at the transformer core with the highest temperature varies from the load of 600(W) to 15.1(°C). In the experiment of efficiency characteristics, the maximum efficiency of 93.5(%) was obtained, and the efficiency improvement of up to 2.8(%) compared to the inverter with Si MOSFET was achieved. The temperature measurement test also shows that most parts temperature is low in the inverter employing SiC MOSFET. The application of SiC MOSFET to the efficiency of inverter was proved to be reasonable as the performance of inverter with SiC

LINK: http://www.mediafire.com/file/w41aw238oiejlv4/A+Study+on+the+Efficiency+Improvement+of+Inverter+for+Automotive+using+SiC+MOSFET.pdf/file

공동주택에 적용한 계통연계형 태양광발전시스템의 보호방식에 관한 연구 A Study on the Protection Method of the Grid-Connected Photovoltaic Power Generation System Applied to Apartments-GeunYub Lee- Dept. of Electrical Eng. The Graduate School Korea University

 

공동주택에 적용한 계통연계형 태양광발전시스템의 보호방식에 관한 연구

 A Study on the Protection Method of the Grid-Connected Photovoltaic Power Generation System Applied to Apartments

 高麗大學敎工學大學院 電氣工學科 李根燁 2011年 

 A Study on the Protection Method of the Grid-Connected Photovoltaic Power Generation System Applied to Apartments 

BY GeunYub Lee 

Dept. of Electrical Eng. The Graduate School Korea University 

(Supervised by Prof. Gilsoo Jang, Ph.D)

 Abstract 

Global environment problems have emerged rapidly throughout international society since the 1990s. Diverse global environment problems are being raised including global warming, ozone depletion, waste contamination, acid rain, desertification, marine pollution, extinction of species, and radioactive contamination. The root cause of these phenomena is energy consumption. Moreover, around a fourth of the total energy consumption is consumed by buildings. In Korea, buildings consume around 25% of the total energy consumption, and residential buildings consume around 75% of energy consumed by buildings and energy consumption by residential buildings is expected to keep growing along with the rise of economic level. Taking this issue seriously, the Korean government has been supporting investments in research and facilities for energy saving and alternative energy technologies since the 1980s as an effort to secure future energy sources, to solve global environment problems, and to attain sustainable economic growth. Recently, facilities using new and renewable energies are being spread and expanded and people are recognizing particularly the importance of technologies for photovoltaic power generation as an infinite energy source. Considering the current situation of Korea highly dependent on fossil energy, the application of photovoltaic power generation to apartment buildings is desirable not only for the growth of national economy and the stable security of alternative energy resources but also for the conservation of global environment. Nevertheless, there have not been many studies for developing technologies to connect photovoltaic systems to electric companies. It is urgently required to increase stable electric power supply of enhanced reliability and to develop system connection technologies. The installation of photovoltaic systems is steadily increasing as evidenced by the onemillion green home construction project under the government’s active support. If photovoltaic facilities are installed on the slanting roofs of apartment buildings and connected to existing distribution systems, they may have an adverse effect on quality, stability and reliability of electric power and, most of all, may disrupt the protective coordination of systems. The connection of photovoltaic systems to distribution systems means a new change in the conventional concept of electric power system. Thus, this study aimed to analyze the quality of electric power required and expected problems when photovoltaic facilities are connected to distribution systems, to look for solutions for the problems, and ultimately to enhance the performance, stability and reliability of photovoltaic systems and establish technological conditions to be satisfied for connection to distribution systems. First, this study examined how to prevent islanding detection caused by power failure in existing distribution systems during the connected operation of photovoltaic facilities and existing distribution systems and to minimize the loss of human life and properties caused by such accidents. Second, this study analyzed the capacity of photovoltaic facilities connectable to low‐voltage distribution systems based on voltage regulation as a part of research on the capacity of photovoltaic systems connected to existing distribution systems. Third, with regard to the ground system of photovoltaic facilities, this study demonstrated the need of a new evaluation method suitable for DC systems apart from existing AC ones. There will be unexpected problems raised along with the spread of system‐connected photovoltaic facilities. Thus we expect active research to find solutions for problems resulting from connection between photovoltaic facilities and distribution systems and to hasten the stable supply of electric power to consumers through photovoltaic facilities using solar energy.

LINK: http://www.mediafire.com/file/k91e2oag6epy4g7/A+Study+on+the+Protection+Method+of+the+Grid-Connected+Photovoltaic+Power+Generation+System+Applied+to+Apartments.pdf/file

MANUAL DE ENGENHARIA PARA SISTEMAS FOTOVOLTAICOS-JOÃO TAVARES PINTO-MARCO ANTONIO GALDINO-GRUPO DE TRABALHO DE ENERGIA SOLAR-GTES-CEPEL-DTE-CRESESB

 
MANUAL DE ENGENHARIA PARA SISTEMAS FOTOVOLTAICOS-JOÃO TAVARES PINTO-MARCO ANTONIO GALDINO-GRUPO DE TRABALHO DE ENERGIA SOLAR-GTES-CEPEL-DTE-CRESESB

LINK: http://www.mediafire.com/file/nd09taqdktrb39r/Manual_de_Engenharia_FV_2014.pdf/file

Control Architecture for Parallel Inverter in Uninterruptible Power Systems Chi Zhang, Student Member, IEEE, Josep M. Guerrero, Fellow, IEEE, Juan C. Vasquez, Senior Member, IEEE, Ernane A.A. Coelho, Member, IEEE

 

Abstract— In this paper, a control strategy for the parallel operation of three-phase inverters forming an online uninterruptible power system (UPS) is presented. The UPS system consists of a cluster of paralleled inverters with LC filters directly connected to an AC critical bus and an AC/DC forming a DC bus. The proposed control scheme comprises two layers: (i) a local layer that contains a “reactive power-to-phase droop” in order to synchronize the phase angle of each inverter and a virtual resistance loop that guarantees equal power sharing among inverters; and (ii) a central controller that guarantees synchronization with an external real/fictitious utility, and critical bus voltage amplitude restoration. Improved transient and steady-state frequency, active, reactive and harmonic power sharing, and global phase-locked loop resynchronization capability are achieved. Detailed system topology and control architecture are presented in this paper. Further, a mathematical model was derived in order to analyze critical parameters effects on system stability. The proposed control approach has been validated by means of experimental results obtained for several case-study scenarios. Index Terms— UPS system; parallel inverters; voltage restoration; droop control; virtual impedance

LINK:https://vbn.aau.dk/files/219215517/Zhang_Chi_trans_manu_doublecol.pdf