Solar Power System Modeling and Performance Analysis Jiaqi Wang Faculty of Engineering and Computer Science University of Denver

Solar Power System Modeling and Performance Analysis Jiaqi Wang Faculty of Engineering and Computer Science University of Denver Author: Jiaqi Wang Title: Solar Power System Modeling and Performance Analysis Advisors: WenZhong Gao Degree Date: August 2011 Abstract At present the main source of our power and energy needs are from fossil fuel; almost all transportation tools and nearly 70% of electrical power are produced by fossil fuel. But unfortunately these materials are limited in our planet, with obvious drawback such as pollution. So looking for new kinds of energy supply is an urgent matter. Solar-powered photovoltaic system provides a clean energy solution to this problem. It is developing fast all over the world in terms of both research work and actual applications. It is estimated that the power supplied by solar energy can provide 10 percent of United States power needs. This thesis mainly discusses photovoltaic system modeling from the beginning of site selection to system sizing. Some tools are used during the project. A GIS application is used to help developers in the preliminary studies. Photovoltaic system simulation software PVsyst involves the system components setting and sizing process. Two types of systems are built in this study: stand-alone system and grid connected system; the location is set at Denver, Colorado. For each system the array mounting, analysis of loads and modules selection are studied. The simulation is performed after the system model is completed, the results includes loss diagrams, system energy yields and system efficiencies. At last the economic analysis and comparison between the two types of PV systems is analyzed.

 LINK
https://digitalcommons.du.edu/cgi/viewcontent.cgi?article=1688&context=etd

Performance of a Single-Stage UPS System for Single-Phase Trapezoidal-Shaped AC-Voltage Supplies Praveen K. Jain, Senior Member, IEEE, Jos´e R. Espinoza, Student Member, IEEE, and Hua Jin, Member, IEEE

Performance of a Single-Stage UPS System for Single-Phase Trapezoidal-Shaped AC-Voltage Supplies Praveen K. Jain, Senior Member, IEEE, Jos´e R. Espinoza, Student Member, IEEE, and Hua Jin, Member, IEEE

 Abstract— A high-performance single-stage UPS system for single-phase ac power supply systems is presented. The topology generates a trapezoidal-shaped load voltage that is synchronized with the ac supply, therefore, a small dc-link capacitor is required. This feature leads to a high-input power factor (0.94 at nominal voltage), and due to the single-stage structure, high efficiency (93% at nominal voltage) is also achieved. Moreover, in both cases the supply current spectrum presents low-order harmonics, all of which satisfy IEC 555. The high performance is validated using both resistive (linear) and diode RC (nonlinear) loads. The dynamic performance of the UPS system is also analyzed under different transient conditions. Specifically, the supply to battery, battery to supply transition, load transient, and supply/battery-voltage transients are performed. They show a transfer time of 500 s (from ac supply to battery) and overvoltages of at most 15%. The dynamic and static evaluations are performed on a 1-kVA UPS system. The design guidelines for the key components and control parameters are also included.
Index Terms— AC mains synchronization, PWM inverter, single-phase single-stage conversion topology, trapezoidal-shaped ac output voltage, UPS.

LINK ORIGINAL
http://www.lcda.cl/descargas/Jain_Espinoza_Jin_.pdf

Simulation and Implementation of Γ-Z Source Inverter G.V.Sreekanth Reddy*, J.N.Chandrasekhar** *(M.Tech, Department of EEE, Sri Venkateswara university College of Engineering, Tirupati ** (Assistant Professor, Department of EEE,Sri Venkateswara university College of Engineering, Tirupati

Simulation and Implementation of Γ-Z Source Inverter

 G.V.Sreekanth Reddy*, J.N.Chandrasekhar** *(M.Tech, Department of EEE, Sri Venkateswara university College of Engineering, Tirupati ** (Assistant Professor, Department of EEE,Sri Venkateswara university College of Engineering, Tirupati

ABSTRACT
This venture "Simulation and Implementation of Γ-Z-Source Inverters" is made out of Voltage-sort Γ-Z source inverters are proposed in this letter. They utilize a remarkable Γ-molded impedance arrange for boosting their yield voltage notwithstanding their standard voltage buck conduct. Contrasting them and different topologies, the proposed inverters utilize lesser parts and a coupled transformer for delivering the high-pick up and regulation proportion all the while. The got pick up can be tuned by changing the turns proportion γΓZ of the transformer inside the limited scope of 1 < γΓZ ≤ 2. This prompts to lesser twisting turns at high pick up, as compared to other related topologies.

 Keywords - Embedded-Z-source, quasi-Z-source, T-source, Trans-Z-source, Z-source, Γ-Z-source inverters.

LINK
http://www.ijera.com/papers/Vol7_issue1/Part-5/A0701050105.pdf

Line-Interactive Transformerless Uninterruptible Power Supply (UPS) with a Fuel Cell as the Primary Source Muhammad Iftikhar , Muhammad Aamir, Asad Waqar , Naila, Fahad Bin Muslim and Imtiaz Alam Department of Electrical Engineering, University of Engineering and Technology,Peshawar, Pakistan

Line-Interactive Transformerless Uninterruptible Power Supply (UPS) with a Fuel Cell as the Primary Source 
 Muhammad Iftikhar , Muhammad Aamir, Asad Waqar , Naila, Fahad Bin Muslim and Imtiaz Alam Department of Electrical Engineering, University of Engineering and Technology,Peshawar, Pakistan

 Abstract: This paper presents line-interactive transformerless Uninterruptible Power Supply (UPS) with a fuel cell as the prime energy source. The proposed UPS consists of three major parts (i.e., an output inverter, a unidirectional DC–DC converter, and a battery charger/discharger). Non-isolated topologies of both the unidirectional converter and battery charger/discharger ensure transformerless operation of the UPS system. A new topology of high gain converter is employed for boosting the low voltage of the fuel cell to a higher DC link voltage, with minimum semiconductor count, and high efficiency. A high-gain battery charger/discharger realizes the bidirectional operation between the DC link and the battery bank. Besides, it regulates the DC link voltage during the cold start of fuel cells and keeps the battery bank voltage to only 24 V. A new inverter control scheme is introduced that regulates the output voltage and minimizes the total harmonic distortion for non-linear loading condition. The proposed control scheme integrates proportional-resonant control with slide mode control, which improves the controller’s performance in transient conditions. The proposed UPS system is validated by developing a 1-kVA experimental prototype.

 Keywords: fuel cell; line-interactive; uninterruptible power supply; transformerless; DC–DC ORIGINAL LINK
https://www.mdpi.com/1996-1073/11/3/542/pdf

INPUT STAGE WITH DOUBLE FUNCTIONALITY APPLIED TO A HIGH PERFORMANCE THREE-PHASE UPS-William A. Venturini, Henrique Jank, Fábio E. Bisogno, Mário L. S. Martins, Humberto Pinheiro Universidade Federal de Santa Maria, Santa Maria – RS-BRASIL

ESTÁGIO DE ENTRADA COM DUPLA FUNCIONALIDADE APLICADO A UMA UPS TRIFÁSICA DE ALTO DESEMPENHO
 William A. Venturini, Henrique Jank, Fábio E. Bisogno, Mário L. S. Martins, Humberto Pinheiro Universidade Federal de Santa Maria, Santa Maria – RS, Brasil

 Resumo – Este trabalho apresenta uma configuração topológica que permite utilizar o estágio de entrada de uma UPS de dupla conversão como retificador trifásico, em modo normal de operação, e como conversor CC/CC elevador de tensão, em modo bateria. Dessa forma, evita-se o uso de um circuito específico para a descarga do banco de baterias, o qual deve ser dimensionado para a potência nominal da UPS. É apresentada a análise de funcionamento do estágio de entrada proposto, bem como a modelagem matemática e o sistema de controle que garantem a aplicabilidade na correção do fator de potência de entrada, no controle da tensão de barramento e ainda no equilíbrio das tensões sobre os capacitores de barramento. A metodologia desenvolvida e a boa performance do sistema proposto são validados através de resultados obtidos em uma plataforma hardware-in-theloop, modelo Typhoon HIL402. Os resultados são adquiridos para uma UPS trifásica de 20 kVA.

Abstract – This work presents a topological configuration that allows the input stage of a double conversion UPS to be used as a three-phase rectifier and a DC/DC voltage boost converter in normal and backup operating mode, respectively. Thus, the use of a specific circuit for the discharge of the battery bank, which would be rated for UPS nominal power, is avoided. The operation analysis of the proposed input stage is presented, as well as the mathematical modeling and the control system that guarantee the applicability in the input power factor correction, DC bus voltage control and for the DC bus capacitors voltage balance. Hardware-in-the-loop results are acquired for a 20 kVA three-phase UPS to validate the developed analysis besides to demonstrate the good performance of the system.

VII. CONCLUSÕES
 Este trabalho apresentou uma configuração topológica de estágio de entrada com dupla funcionalidade aplicado a uma UPS de alto desempenho. A característica de dupla funcionalidade é evidenciada pelo uso do mesmo circuito para condicionar a energia demandada pela carga, tanto em modo normal, quanto em modo bateria de operação, operando como um retificador trifásico e como um conversor CC/CC elevador de tensão para a descarga do banco de baterias, respectivamente. Esta característica não é observada na literatura, sendo usualmente utilizado um conversor específico para a descarga do banco de baterias, o qual deve ser dimensionado para a potência nominal da UPS. É apresentada a modelagem de pequenos sinais e o projeto dos controladores que garantem a funcionalidade do estágio de entrada proposto. A metodologia de projeto e o desempenho da topologia em questão são validados a partir de resultados obtidos através de uma plataforma
hardware-in-the-loop de alta fidelidade para uma UPS de 20 kVA.

AGRADECIMENTOS Os autores gostariam de agradecer ao CNPq, CAPES e grupo LEGRAND pelo suporte financeiro a esta pesquisa.

  Palavras-Chave – Correção do Fator de Potência, Fonte Ininterrupta de Energia, Retificador Trifásico.
LINK FULL PAPER
https://www.sobraep.org.br/site/uploads/2018/06/rvol23no2p21.pdf