In modern life, human have become dependent on portable electronics, such as cell phones, MP3 and handheld computers, most of which are powered by batteries. Although the performance of batteries is being continuously improved, the limited energy storage and service life constrain the lasting use of these mobile electronics. Therefore it is desirable to find alternative or supplementary methods to solve this problem from its root cause. It is known that human body contains rich chemical energy, part of which is converted to mechanical energy up to 200W when in motion, so it is ideal to harvest a small fraction of the human kinetic energy to power mobile electronic devices. / In this thesis, first, the previous work done by other researchers on energy harvesting from human motion, especially from unintentional human motion, such as arm swing and leg moving, is reviewed. Then the fundamental principles to mechanically harvest motion energy are discussed, including the mechanical oscillating mechanisms and electromagnetic transduction. Derived from the general harvesting model, four different devices are designed and analyzed. / Shoe is important for human, one of which functions is to serve as shock-absorber to protect foot from the large impact force. As the foot strikes the ground, the shoe is subject to not only large force but also large displacement in the heel. The third new device is designed to insert in the shoe heel to harvest the kinetic energy from foot strike, and at the same time to function as a shock absorber for foot. Considering the stability and efficiency, a spring-slider-crank mechanism is used in this harvester to covert the up-down foot strike motion into unidirectional rotation to drive an AC generator. The spring and slider compose an oscillating system to absorb the foot strike motion, and crank and slider make up the conversion mechanism to transfer the bi-directional translation into unidirectional rotation. A set of gear is used to speed up the rotation. The kinematical performance of the harvester is also analyzed. / The first one is the automatic winding mechanism of mechanical movement. It consists of an oscillating weight, a ratchet mechanism, a gear set and a mainspring. The mechanism can be modeled as a double pendulum when worn on a user's wrist. Its kinematical performance is analyzed with experimental validation. / This thesis discusses the feasibility of mechanical power generators driven by human motion, with the focus on their architecture design and performance analysis. The main objective is to develop effective power generators for harvesting the energy from human motion, and use it to power portable electronic devices. / To directly convert the human arm motion to electricity, the second novel energy harvester is designed, analyzed and simulated. It mainly consists of an eccentric rotor made of permanent magnet, and a set of coils as a stator. The eccentric rotor, as a simple pendulum, acts as the kinetic energy harvester which absorbs the motion from human body in motion. With the permanent magnets on the rotor, the moving rotor produces a changing magnetic field, from which the stator induces electricity. In this design, a torsion spring is also added onto the rotor so that the harvester works even when the motion is on horizontal plane. / When foot strikes the ground, a large acceleration is produced. The fourth new energy harvester uses dual-oscillating mode. It contains two oscillating mechanisms: one is spring-mass oscillator to absorb the vibration from footstep motion, and the other is cantilever beam using the tip mass to amplify the vibration. Analysis shows that the dual-oscillating mechanism can be more effectively harvest the foot step motion. The energy conversion sub-mechanism is based on the electromagnetic induction, where the coils fixed at the tip end of the cantilever beam serves as the slider, and the fixed permanent magnets and yoke produce the changing magnetic field. Mathematical analysis and simulation are included. / Xie, Longhan. / Adviser: Ruxu Du. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 124-128). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / Ph.D.

Smart grid has been described as the Energy Internet: Where Energy Technology meets Information Technology. The incorporation of such technology into vast existing utility infrastructures offers many advantages, including possibilities for new smart appliances, energy management systems, better integration of renewable energy, value added services, and new business models, both for supply- and demand-side management. Smart grid also replaces aging utility technologies that are becoming increasingly unreliable, as the average ages for many critical components in utility systems now exceed their original design lives. However, while smart grid offers the promise of revolutionizing utility delivery systems, many questions remain about how such systems can be rolled out at the state, regional, and national levels. Many unique regulatory and market structure challenges exist, which makes it critical to pick the right technology for the right situation and to employ it in the right manner. Technology Roadmapping may be a valuable approach for helping to understand factors that could affect smart grid technology and product development, as well as key business, policy and regulatory drivers. As emerging smart grid technologies are developed and the fledgling industry matures, a critical issue will be understanding how the combination of industry drivers impact one another, what barriers exist to achieving the benefits of smart grid technologies, and how to prioritize R&D and acquisition efforts. Since the planning of power grids often relies on regional factors, it will also be important investigate linkages between smart grid deployment and regional planning goals. This can be used to develop strategies for overcoming barriers and achieving the benefits of this promising new technology. This research builds upon existing roadmapping processes by considering an integrated set of factors, including policy issues, which are specifically tuned to the needs of smart grids and have not generally been considered in other types of roadmapping efforts. It will also incorporate expert judgment quantification to prioritize factors, show the pathways for overcoming barriers and achieving benefits, and discussing the most promising strategies for achieving these goals.

Abstract not available

Remote area power supply (RAPS) is a potential early market for renewable energy - hydrogen systems because of the relatively high costs of conventional energy sources in remote regions. Solar-hydrogen RAPS systems commonly employ photovoltaic panels, a Proton Exchange Membrane (PEM) electrolyser, a storage for hydrogen gas, and a PEM fuel cell. Unitised Regenerative Fuel Cells (URFCs) use the same hardware for both electrolyser and fuel cell functions. Since both of these functions are not required simultaneously in a solar hydrogen RAPS system, URFCs based on PEM technology provide a promising opportunity for reducing the cost of the hydrogen subsystem used in renewable-energy hydrogen systems for RAPS. URFCs also have potential applications in the areas of aerospace, submarines, energy storage for central grids, and hydrogen cars. In this thesis, a general theoretical relationship between cell potential and current density of a single-cell PEM URFC operating in both fuel-cell (FC) and electrolyser (E) modes is developed using modified Butler-Volmer equations for both oxygen- and hydrogen-electrodes, and accounting for mass transport losses and saturation behaviour in both modes, membrane resistance to proton current, and membrane and electrode resistances to electron current. This theoretical relationship is used to construct a computer model based on Excel and Visual Basic to generate voltage-current (V-I) polarisation curves in both E and FC modes for URFCs with a range of membrane electrode assembly characteristics. The model is used to investigate the influence on polarisation curves of varying key parameters such charge transfer coefficients, exchange current densities, saturation currents, and membrane conductivity. A method for using the model to obtain best-fit values for electrode characteristics corresponding to an experime ntally-measured polarisation curve of a URFC is presented. The experimental component of the thesis has involved the design and construction of single PEM URFCs with an active area of 5 cm2 with a number of different catalyst types and loadings. V-I curves for all these cells have been measured and the performance of the cells compared. The computer model has then been used to obtain best-fit values for the electrode characteristics for the URFCs with single catalyst materials active in each mode on each electrode for the corresponding experimentally-measured V-I curves. Generally values have been found for exchange current densities, charge transfer coefficients, and saturation current densities that give a close fit between the empirical and theoretically-generated curves. The values found conform well to expectations based on the catalyst loadings, in partial confirmation of the validity of the modelling approach. The model thus promises to be a useful tool in identifying electrodes with materials and structures, together with optimal catalyst types and loadings that will improve URFC performance. Finally the role URFCs can play in developing cost-competitive solar- hydrogen RAPS systems is discussed, and some future directions for future URFC research and development are identified.

<p>Multiple causes of continuously occurring power outages in Yazd Province of Iran have been experienced in recent years. This research studies how key stakeholders have perceived the results of the strategic decisions taken by directors of HEPP to diminish the power shortages and to even increase power supply to a limit of exporting power to other neighboring provinces. How could HEPP emerge from an organization in the edge of bankruptcy to an organization that can surpass all expectations and won over their competitors? HEPP’s strategic decisions followed implications of several models and finally a strategic plan on the bases of the Bryson model was selected and practically applied to achieve their final expected results. The literature review in this study describes selected models as well as the Bryson model set up and structure. This study portrays a demonstration and an evaluation of various strategic plan management models used in Iranian organization in particular HEPP. The researcher designed several questionnaires and forwarded them to HEPP’s administrators, employees and other stakeholders in three groups. Additional phone interviews were conducted and the quantitative as well as qualitative data collected was evaluated and displayed in tables and figures in this study. Data analysis demonstrates a few shortcomings, weaknesses and strengths that are discussed in detail and conclusive proposals are presented through the conclusion section in enhancement of HEPP’s services to the advantages of stakeholders and employees of HEPP with a complete consideration for HEPP’s well being and awareness of its competitors. Although this study is limited in scope it highlights what needs to be done in HEPP or similar hydro electric organizations in Iran, and it can act as a stepping stone for further research and analysis of hydro electrical demand and supply issues in Yazd region of Iran.</p>

Power and timing requirements are becoming more and more stringent as applications move from less mobile devices to more mobile ones. As such, it is important to optimize these applications as much as possible in order to provide the best solution that is low power and low latency. Although there are many different techniques to achieve a low power, low latency solution, this thesis focuses specifically on low power scheduling at the behavioral level where resource-constrained scheduling is the technique of choice since it directly considers the resource limitations of mobile devices. Conventional resource-constrained scheduling schemes are concerned with minimizing the latency or improving the speed of an algorithm--represented by a data flow graph (DFG)--given a limitation on resources. However, these conventional resource-constrained scheduling schemes are no longer applicable since power has grown to be a major issue, especially in mobile devices. Hence, the conventional resource-constrained scheduling schemes gave way to current resource-constrained scheduling schemes that utilize multiple voltages, which work to find a balance between speed and power. These current multiple voltage schemes use various techniques to balance and meet the speed and power requirements. But while they do a good job of meeting these requirements, they fail to address a new issue that is beginning to surface the number of memory registers needed. Therefore, to address this new arising issue, this paper presents a novel resource-constrained scheduling scheme that balances the speed, power, and register requirements. This algorithm is compared to both a conventional resource-constrained scheduling scheme and a current resource-constrained scheduling scheme with multiple voltages to show that it performs better in finding a scheduling solution. Benchmark results show that, on average, our algorithm has a better power savings while keeping the maximum number of registers needed and the latency low compared to conventional resource-constrained scheduling schemes and current resource-constrained scheduling schemes utilizing just multiple voltages. / Graduation date: 2004

This dissertation proposes a novel control technique for power density maximization of the brushless DC (BLDC) generator which is a nonsinusoidal power supply system. In a generator of given rating, the weight and size of the system affect the fuel consumption directly, therefore power density is one of the most important issues in a stand-alone generator. Conventional rectification methods cannot achieve the maximum power possible because of a distorted or unsuitable current waveform. The optimal current waveform for maximizing power density and minimizing machine size and weight in a nonsinusoidal power supply system has been proposed theoretically and verified by simulation and experimental work. Also, various attributes of practical interest are analyzed and simulated to investigate the impact on real systems.

This master thesis describes the development of an UPS module. UPS is an acronym for Uninterruptable Power Supply. The UPS module has been developed at the company AerotechTelub AB. The UPS module delivers the necessary voltage and current in case of a power interrupt. If a power interrupt occur, the computer system has one to three minutes available to store data and shut down correctly. The UPS module consists of two parallel systems. Every system is built out of four parts. Part one consists of batteries and safety circuits, part two charges the batteries, partthree is a control unit, and part four delivers the voltage and current. The delivered voltage is 5 V and the current is 4 A. Tests and verifications showed that the UPS module could supply a computer system with power for about one minute. The tests have been performed in a lab at AerotechTelub AB. The UPS module is supposed to be mounted in a cassette. The cassette is then inserted in the computer system through a hole in the chassis. Thereby an opening of the computer system is avoided when the module is connected.

Multiple causes of continuously occurring power outages in Yazd Province of Iran have been experienced in recent years. This research studies how key stakeholders have perceived the results of the strategic decisions taken by directors of HEPP to diminish the power shortages and to even increase power supply to a limit of exporting power to other neighboring provinces. How could HEPP emerge from an organization in the edge of bankruptcy to an organization that can surpass all expectations and won over their competitors? HEPP’s strategic decisions followed implications of several models and finally a strategic plan on the bases of the Bryson model was selected and practically applied to achieve their final expected results. The literature review in this study describes selected models as well as the Bryson model set up and structure. This study portrays a demonstration and an evaluation of various strategic plan management models used in Iranian organization in particular HEPP. The researcher designed several questionnaires and forwarded them to HEPP’s administrators, employees and other stakeholders in three groups. Additional phone interviews were conducted and the quantitative as well as qualitative data collected was evaluated and displayed in tables and figures in this study. Data analysis demonstrates a few shortcomings, weaknesses and strengths that are discussed in detail and conclusive proposals are presented through the conclusion section in enhancement of HEPP’s services to the advantages of stakeholders and employees of HEPP with a complete consideration for HEPP’s well being and awareness of its competitors. Although this study is limited in scope it highlights what needs to be done in HEPP or similar hydro electric organizations in Iran, and it can act as a stepping stone for further research and analysis of hydro electrical demand and supply issues in Yazd region of Iran.