High gain non-isolated DC-DC converter topologies for energy conversion systems

PhD ThesisEmerging applications driven by low voltage level power sources, such as photovoltaics, batteries and fuel cells require static power converters for appropriate energy conversion and conditioning to supply the requirements of the load system. Increasingly, for applications such as grid connected inverters, uninterruptible power supplies (UPS), and electric vehicles (EV), the performance of a high efficiency high static gain power converter is of critical importance to the overall system. Theoretically, the conventional boost and buck-boost converters are the simplest non-isolated topologies for voltage step-up. However, these converters typically operate under extreme duty ratio, and severe output diode reverse recovery related losses to achieve high voltage gain. This thesis presents derivation, analysis and design issues of advanced high step-up topologies with coupled inductor and voltage gain extension cell. The proposed innovative solution can achieve significant performance improvement compared to the recently proposed state of the art topologies. Two unique topologies employing coupled inductor and voltage gain extension cell are proposed. Power converters utilising coupled inductors traditionally require a clamp circuit to limit the switch voltage excursion. Firstly, a simple low-cost, high step-up converters employing active and passive clamp scheme is proposed. Performance comparison of the clamps circuits shows that the active clamp solution can achieve higher efficiency over the passive solution. Secondly, the primary detriment of increasing the power level of a coupled inductor based converters is high current ripple due to coupled inductor operation. It is normal to interleaved DC-DC converters to share the input current, minimize the current ripple and increase the power density. This thesis presents an input parallel output series converter integrating coupled inductors and switched capacitor demonstrating high static gain. Steady state analysis of the converter is presented to determine the power flow equations. Dynamic analysis is performed to design a closed loop controller to regulate the output voltage of the interleaved converter. The design procedure of the high step-up converters is explained, simulation and experimental results of the laboratory prototypes are presented. The experimental results obtained via a 250 W single phase converter and that of a 500 W interleaved converter prototypes; validate both the theory and operational characteristics of each power converter.Petroleum Technology Development Fund (PTDF) Nigeri

Wind Farm

During the last two decades, increase in electricity demand and environmental concern resulted in fast growth of power production from renewable sources. Wind power is one of the most efficient alternatives. Due to rapid development of wind turbine technology and increasing size of wind farms, wind power plays a significant part in the power production in some countries. However, fundamental differences exist between conventional thermal, hydro, and nuclear generation and wind power, such as different generation systems and the difficulty in controlling the primary movement of a wind turbine, due to the wind and its random fluctuations. These differences are reflected in the specific interaction of wind turbines with the power system. This book addresses a wide variety of issues regarding the integration of wind farms in power systems. The book contains 14 chapters divided into three parts. The first part outlines aspects related to the impact of the wind power generation on the electric system. In the second part, alternatives to mitigate problems of the wind farm integration are presented. Finally, the third part covers issues of modeling and simulation of wind power system

NASA Tech Briefs, May/June 1986

Topics discussed include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

Energy Markets and Economics Ⅱ

This issue brings together a collection of papers that provide economic insights into the modern energy market, which is still dominated by crude oil but has expanded to incorporate new energy sources in the form of coal, natural gas, and a mixture of renewable energy sources. Given the differences in the dynamics at play with different energy sources, particularly in relation to price determination, the impact they have on the environment, their importance in the energy mix and energy policy, and so forth, it has become imperative to check their behavior using economic models. Papers 1–3 provide some perspective on oil price determination by focusing on the time-varying nature of supply shocks linked to oil producers (Paper 1), OPEC’s announcements (2), and the heterogeneous interconnections of supply or demand shocks over time horizons and different countries (3). Papers 4–6 compare different energy sources within the energy market and other markets (4); explore the importance of energy storage in the electricity market (5); and examine the dynamic relationship between prices of substitutes (oil price) on the natural gas market in China (6). The final four studies examine the impact of renewable and nonrenewable energy on the macroeconomy and the environment

Design principles for the development of space technology maturation laboratories aboard the International Space Station

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2005.Includes bibliographical references (v. 2, p. 339-349).This thesis formulates seven design principles for the development of laboratories which utilize the International Space Station (ISS) to demonstrate the maturation of space technologies. The principles are derived from the lessons learned from more than two decades of space technology research at the MIT Space Systems Laboratory and the existence of unique resources aboard the ISS. The thesis provides scientists with a design framework for new laboratories and an evaluation framework to responds to a call by the National Research Council to institutionalize science activities aboard the ISS. Experience from previous missions and research on the resources available at the ISS led to the development of the SPHERES Laboratory for Distributed Satellite Systems (DSS), which constitutes the experimental part of the thesis. SPHERES allows tests in a representative, risk-tolerant environment aboard the ISS to demonstrate metrology, control, and autonomy algorithms for DSS. The implementation of ground-based and ISS-based facilities permits incremental technology maturation by enabling iterative research; algorithms can mature through multiple research cycles with increasing complexity. The SPHERES Guest Scientist Program supports research by multiple scientists: since the Spring of 2000 SPHERES has enabled research on formation flight, communications requirements, mass properties identification, autonomous rendezvous and docking, and tethered formation flight.(cont.) The design principles were formulated by first identifying the features of the SPHERES laboratory which allow it to fulfill the MIT SSL Laboratory Design Philosophy and utilize the ISS correctly, and then finding the applicability of these features to space technology maturation research. The seven principles are: Principle of Iterative Research, Principle of Enabling a Field of Study, Principle of Optimized Utilization, Principle of Focused Modularity, Principle of Remote Operations and Usability, Principle of Incremental Technology Maturation, and Principle of Requirements Balance. The design framework is used to assess SPHERES and suggest a new design iteration which better satisfies the design principles. The evaluation of SPHERES concludes that it is ready for operations aboard the ISS, since the modular design of SPHERES allows most of the proposed design changes to occur after the initial deployment.by Alvar Saenz-Otero.Ph.D

Design Development Test and Evaluation (DDT and E) Considerations for Safe and Reliable Human Rated Spacecraft Systems

A team directed by the NASA Engineering and Safety Center (NESC) collected methodologies for how best to develop safe and reliable human rated systems and how to identify the drivers that provide the basis for assessing safety and reliability. The team also identified techniques, methodologies, and best practices to assure that NASA can develop safe and reliable human rated systems. The results are drawn from a wide variety of resources, from experts involved with the space program since its inception to the best-practices espoused in contemporary engineering doctrine. This report focuses on safety and reliability considerations and does not duplicate or update any existing references. Neither does it intend to replace existing standards and policy

Proceedings of the 8th International Conference on Energy Efficiency in Domestic Appliances and Lighting

At the EEDAL'15 conference 128 papers dealing with energy consumption and energy efficiency improvements for the residential sector have been presented. Papers focused policies and programmes, technologies and consumer behaviour. Special focus was on standards and labels, demand response and smart meters. All the paper s have been peer reviewed by experts in the sector.JRC.F.7-Renewables and Energy Efficienc

Planet Earth 2011

The failure of the UN climate change summit in Copenhagen in December 2009 to effectively reach a global agreement on emission reduction targets, led many within the developing world to view this as a reversal of the Kyoto Protocol and an attempt by the developed nations to shirk out of their responsibility for climate change. The issue of global warming has been at the top of the political agenda for a number of years and has become even more pressing with the rapid industrialization taking place in China and India. This book looks at the effects of climate change throughout different regions of the world and discusses to what extent cleantech and environmental initiatives such as the destruction of fluorinated greenhouse gases, biofuels, and the role of plant breeding and biotechnology. The book concludes with an insight into the socio-religious impact that global warming has, citing Christianity and Islam

Safety and Reliability - Safe Societies in a Changing World

The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen

Understanding Quantum Technologies 2022

Understanding Quantum Technologies 2022 is a creative-commons ebook that provides a unique 360 degrees overview of quantum technologies from science and technology to geopolitical and societal issues. It covers quantum physics history, quantum physics 101, gate-based quantum computing, quantum computing engineering (including quantum error corrections and quantum computing energetics), quantum computing hardware (all qubit types, including quantum annealing and quantum simulation paradigms, history, science, research, implementation and vendors), quantum enabling technologies (cryogenics, control electronics, photonics, components fabs, raw materials), quantum computing algorithms, software development tools and use cases, unconventional computing (potential alternatives to quantum and classical computing), quantum telecommunications and cryptography, quantum sensing, quantum technologies around the world, quantum technologies societal impact and even quantum fake sciences. The main audience are computer science engineers, developers and IT specialists as well as quantum scientists and students who want to acquire a global view of how quantum technologies work, and particularly quantum computing. This version is an extensive update to the 2021 edition published in October 2021.Comment: 1132 pages, 920 figures, Letter forma